changeset 948:e5288029f850

RBTree fix
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Sat, 20 Jul 2024 17:01:50 +0900
parents 91137bc52ddd
children 057d3309ed9d
files RBTree.agda RBTree0.agda logic.agda
diffstat 3 files changed, 2389 insertions(+), 312 deletions(-) [+]
line wrap: on
line diff
--- a/RBTree.agda	Tue Jul 09 08:51:13 2024 +0900
+++ b/RBTree.agda	Sat Jul 20 17:01:50 2024 +0900
@@ -1,3 +1,5 @@
+{-# OPTIONS  --allow-unsolved-metas #-}
+-- {-# OPTIONS --cubical-compatible --allow-unsolved-metas #-}
 module RBTree where
 
 open import Level hiding (suc ; zero ; _⊔_ )
@@ -155,7 +157,7 @@
    → treeInvariant (node kp value₂ tree  tree₃ )
    → stackInvariant key tree orig (tree ∷ node kp value₂ tree  tree₃ ∷ stack)
    → key < kp
-si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x s-nil) = ⊥-elim (nat-<> x₁ x₂)
+si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right (node _ _ _ _) _ (node _ _ _ _) x s-nil) = ⊥-elim (nat-<> x₁ x₂)
 si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x (s-right .(node _ _ (node _ _ _ _) (node _ _ _ _)) _ tree₁ x₇ si)) = ⊥-elim (nat-<> x₁ x₂)
 si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x (s-left .(node _ _ (node _ _ _ _) (node _ _ _ _)) _ tree x₇ si)) = ⊥-elim (nat-<> x₁ x₂)
 si-property-< ne ti (s-left _ _ _ x (s-right .(node _ _ _ _) _ tree₁ x₁ si)) = x
@@ -328,253 +330,6 @@
      ... | tri≈ ¬a b ¬c = refl
      ... | tri> ¬a ¬b c = ⊥-elim (¬b (sym lt1))
 
-record replacePR {n : Level} {A : Set n} (key : ℕ) (value : A) (tree repl : bt A ) (stack : List (bt A)) (C : bt A → bt A → List (bt A) → Set n) : Set n where
-   field
-     tree0 : bt A
-     ti : treeInvariant tree0
-     si : stackInvariant key tree tree0 stack
-     ri : replacedTree key value (child-replaced key tree ) repl
-     ci : C tree repl stack     -- data continuation
-
-record replacePR' {n : Level} {A : Set n} (key : ℕ) (value : A) (orig : bt A ) (stack : List (bt A))  : Set n where
-   field
-     tree repl : bt A
-     ti : treeInvariant orig
-     si : stackInvariant key tree orig stack
-     ri : replacedTree key value (child-replaced key tree) repl
-     --   treeInvariant of tree and repl is inferred from ti, si and ri.
-
-replaceNodeP : {n m : Level} {A : Set n} {t : Set m} → (key : ℕ) → (value : A) → (tree : bt A)
-    → (tree ≡ leaf ) ∨ ( node-key tree ≡ just key )
-    → (treeInvariant tree ) → ((tree1 : bt A) → treeInvariant tree1 →  replacedTree key value (child-replaced key tree) tree1 → t) → t
-replaceNodeP k v1 leaf C P next = next (node k v1 leaf leaf) (t-single k v1 ) r-leaf
-replaceNodeP k v1 (node .k value t t₁) (case2 refl) P next = next (node k v1 t t₁) (replaceTree1 k value v1 P)
-     (subst (λ j → replacedTree k v1 j  (node k v1 t t₁) ) repl00 r-node) where
-         repl00 : node k value t t₁ ≡ child-replaced k (node k value t t₁)
-         repl00 with <-cmp k k
-         ... | tri< a ¬b ¬c = ⊥-elim (¬b refl)
-         ... | tri≈ ¬a b ¬c = refl
-         ... | tri> ¬a ¬b c = ⊥-elim (¬b refl)
-
-replaceP : {n m : Level} {A : Set n} {t : Set m}
-     → (key : ℕ) → (value : A) → {tree : bt A} ( repl : bt A)
-     → (stack : List (bt A)) → replacePR key value tree repl stack (λ _ _ _ → Lift n ⊤)
-     → (next : ℕ → A → {tree1 : bt A } (repl : bt A) → (stack1 : List (bt A))
-         → replacePR key value tree1 repl stack1 (λ _ _ _ → Lift n ⊤) → length stack1 < length stack → t)
-     → (exit : (tree1 repl : bt A) → treeInvariant tree1 ∧ replacedTree key value tree1 repl → t) → t
-replaceP key value {tree}  repl [] Pre next exit = ⊥-elim ( si-property0 (replacePR.si Pre) refl ) -- can't happen
-replaceP key value {tree}  repl (leaf ∷ []) Pre next exit with  si-property-last  _ _ _ _  (replacePR.si Pre)-- tree0 ≡ leaf
-... | refl  =  exit (replacePR.tree0 Pre) (node key value leaf leaf) ⟪ replacePR.ti Pre ,  r-leaf ⟫
-replaceP key value {tree}  repl (node key₁ value₁ left right ∷ []) Pre next exit with <-cmp key key₁
-... | tri< a ¬b ¬c = exit (replacePR.tree0 Pre) (node key₁ value₁ repl right ) ⟪ replacePR.ti Pre , repl01 ⟫ where
-    repl01 : replacedTree key value (replacePR.tree0 Pre) (node key₁ value₁ repl right )
-    repl01 with si-property1 (replacePR.si Pre) | si-property-last  _ _ _ _  (replacePR.si Pre)
-    repl01 | refl | refl = subst (λ k → replacedTree key value  (node key₁ value₁ k right ) (node key₁ value₁ repl right )) repl02 (r-left a repl03) where
-        repl03 : replacedTree key value ( child-replaced key (node key₁ value₁ left right)) repl
-        repl03 = replacePR.ri Pre
-        repl02 : child-replaced key (node key₁ value₁ left right) ≡ left
-        repl02 with <-cmp key key₁
-        ... | tri< a ¬b ¬c = refl
-        ... | tri≈ ¬a b ¬c = ⊥-elim ( ¬a a)
-        ... | tri> ¬a ¬b c = ⊥-elim ( ¬a a)
-... | tri≈ ¬a b ¬c = exit (replacePR.tree0 Pre) repl ⟪ replacePR.ti Pre , repl01 ⟫ where
-    repl01 : replacedTree key value (replacePR.tree0 Pre) repl
-    repl01 with si-property1 (replacePR.si Pre) | si-property-last  _ _ _ _  (replacePR.si Pre)
-    repl01 | refl | refl = subst (λ k → replacedTree key value k repl) repl02 (replacePR.ri Pre) where
-        repl02 : child-replaced key (node key₁ value₁ left right) ≡ node key₁ value₁ left right
-        repl02 with <-cmp key key₁
-        ... | tri< a ¬b ¬c = ⊥-elim ( ¬b b)
-        ... | tri≈ ¬a b ¬c = refl
-        ... | tri> ¬a ¬b c = ⊥-elim ( ¬b b)
-... | tri> ¬a ¬b c = exit (replacePR.tree0 Pre) (node key₁ value₁ left repl  ) ⟪ replacePR.ti Pre , repl01 ⟫ where
-    repl01 : replacedTree key value (replacePR.tree0 Pre) (node key₁ value₁ left repl )
-    repl01 with si-property1 (replacePR.si Pre) | si-property-last  _ _ _ _  (replacePR.si Pre)
-    repl01 | refl | refl = subst (λ k → replacedTree key value  (node key₁ value₁ left k ) (node key₁ value₁ left repl )) repl02 (r-right c repl03) where
-        repl03 : replacedTree key value ( child-replaced key (node key₁ value₁ left right)) repl
-        repl03 = replacePR.ri Pre
-        repl02 : child-replaced key (node key₁ value₁ left right) ≡ right
-        repl02 with <-cmp key key₁
-        ... | tri< a ¬b ¬c = ⊥-elim ( ¬c c)
-        ... | tri≈ ¬a b ¬c = ⊥-elim ( ¬c c)
-        ... | tri> ¬a ¬b c = refl
-replaceP {n} {_} {A} key value  {tree}  repl (leaf ∷ st@(tree1 ∷ st1)) Pre next exit = next key value repl st Post ≤-refl where
-    Post :  replacePR key value tree1 repl (tree1 ∷ st1) (λ _ _ _ → Lift n ⊤)
-    Post with replacePR.si Pre
-    ... | s-right  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 tree₁ leaf
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl07 : child-replaced key (node key₂ v1 tree₁ leaf) ≡ leaf
-        repl07 with <-cmp key key₂
-        ... |  tri< a ¬b ¬c = ⊥-elim (¬c x)
-        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬c x)
-        ... |  tri> ¬a ¬b c = refl
-        repl12 : replacedTree key value (child-replaced key  tree1  ) repl
-        repl12 = subst₂ (λ j k → replacedTree key value j k ) (sym (subst (λ k → child-replaced key k ≡ leaf) (sym repl09) repl07 ) ) (sym (rt-property-leaf (replacePR.ri Pre))) r-leaf
-    ... | s-left  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 leaf tree₁
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl07 : child-replaced key (node key₂ v1 leaf tree₁ ) ≡ leaf
-        repl07 with <-cmp key key₂
-        ... |  tri< a ¬b ¬c = refl
-        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬a x)
-        ... |  tri> ¬a ¬b c = ⊥-elim (¬a x)
-        repl12 : replacedTree key value (child-replaced key  tree1  ) repl
-        repl12 = subst₂ (λ j k → replacedTree key value j k ) (sym (subst (λ k → child-replaced key k ≡ leaf) (sym repl09) repl07) ) (sym (rt-property-leaf (replacePR.ri Pre ))) r-leaf
-       -- repl12 = subst₂ (λ j k → replacedTree key value j k ) (sym (subst (λ k → child-replaced key k ≡ leaf) (sym repl09) repl07 ) ) (sym (rt-property-leaf (replacePR.ri Pre))) r-leaf
-replaceP {n} {_} {A} key value {tree}  repl (node key₁ value₁ left right ∷ st@(tree1 ∷ st1)) Pre next exit  with <-cmp key key₁
-... | tri< a ¬b ¬c = next key value (node key₁ value₁ repl right ) st Post ≤-refl where
-    Post : replacePR key value tree1 (node key₁ value₁ repl right ) st (λ _ _ _ → Lift n ⊤)
-    Post with replacePR.si Pre
-    ... | s-right _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 tree₁ (node key₁ value₁ left right)
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl03 : child-replaced key (node key₁ value₁ left right) ≡ left
-        repl03 with <-cmp key key₁
-        ... | tri< a1 ¬b ¬c = refl
-        ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
-        ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
-        repl02 : child-replaced key (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡ node key₁ value₁ left right
-        repl02 with repl09 | <-cmp key key₂
-        ... | refl | tri< a ¬b ¬c = ⊥-elim (¬c lt)
-        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬c lt)
-        ... | refl | tri> ¬a ¬b c = refl
-        repl04 : node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡ child-replaced key tree1
-        repl04  = begin
-            node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡⟨ cong (λ k → node key₁ value₁ k right) repl03  ⟩
-            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
-            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
-            child-replaced key tree1 ∎  where open ≡-Reasoning
-        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ repl right)
-        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ repl right) ) repl04  (r-left a (replacePR.ri Pre))
-    ... | s-left _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 (node key₁ value₁ left right) tree₁
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl03 : child-replaced key (node key₁ value₁ left right) ≡ left
-        repl03 with <-cmp key key₁
-        ... | tri< a1 ¬b ¬c = refl
-        ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
-        ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
-        repl02 : child-replaced key (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡ node key₁ value₁ left right
-        repl02 with repl09 | <-cmp key key₂
-        ... | refl | tri< a ¬b ¬c = refl
-        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬a lt)
-        ... | refl | tri> ¬a ¬b c = ⊥-elim (¬a lt)
-        repl04 : node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡ child-replaced key tree1
-        repl04  = begin
-            node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡⟨ cong (λ k → node key₁ value₁ k right) repl03  ⟩
-            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
-            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
-            child-replaced key tree1 ∎  where open ≡-Reasoning
-        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ repl right)
-        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ repl right) ) repl04  (r-left a (replacePR.ri Pre))
-... | tri≈ ¬a b ¬c = next key value (node key₁ value  left right ) st Post ≤-refl where
-    Post :  replacePR key value tree1 (node key₁ value left right ) (tree1 ∷ st1) (λ _ _ _ → Lift n ⊤)
-    Post with replacePR.si Pre
-    ... | s-right  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 b ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 tree₁ tree -- (node key₁ value₁  left right)
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl07 : child-replaced key (node key₂ v1 tree₁ tree) ≡ tree
-        repl07 with <-cmp key key₂
-        ... |  tri< a ¬b ¬c = ⊥-elim (¬c x)
-        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬c x)
-        ... |  tri> ¬a ¬b c = refl
-        repl12 : (key ≡ key₁) → replacedTree key value (child-replaced key  tree1  ) (node key₁ value left right )
-        repl12 refl with repl09
-        ... | refl = subst (λ k → replacedTree key value k (node key₁ value left right )) (sym repl07) r-node
-    ... | s-left  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 b ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 tree tree₁
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl07 : child-replaced key (node key₂ v1 tree tree₁ ) ≡ tree
-        repl07 with <-cmp key key₂
-        ... |  tri< a ¬b ¬c = refl
-        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬a x)
-        ... |  tri> ¬a ¬b c = ⊥-elim (¬a x)
-        repl12 : (key ≡ key₁) → replacedTree key value (child-replaced key  tree1  ) (node key₁ value left right )
-        repl12 refl with repl09
-        ... | refl = subst (λ k → replacedTree key value k (node key₁ value left right )) (sym repl07) r-node
-... | tri> ¬a ¬b c = next key value (node key₁ value₁ left repl ) st Post ≤-refl where
-    Post : replacePR key value tree1 (node key₁ value₁ left repl ) st (λ _ _ _ → Lift n ⊤)
-    Post with replacePR.si Pre
-    ... | s-right _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 tree₁ (node key₁ value₁ left right)
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl03 : child-replaced key (node key₁ value₁ left right) ≡ right
-        repl03 with <-cmp key key₁
-        ... | tri< a1 ¬b ¬c = ⊥-elim (¬c c)
-        ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
-        ... | tri> ¬a ¬b c = refl
-        repl02 : child-replaced key (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡ node key₁ value₁ left right
-        repl02 with repl09 | <-cmp key key₂
-        ... | refl | tri< a ¬b ¬c = ⊥-elim (¬c lt)
-        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬c lt)
-        ... | refl | tri> ¬a ¬b c = refl
-        repl04 : node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡ child-replaced key tree1
-        repl04  = begin
-            node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡⟨ cong (λ k → node key₁ value₁ left k ) repl03 ⟩
-            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
-            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
-            child-replaced key tree1 ∎  where open ≡-Reasoning
-        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ left repl)
-        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ left repl) ) repl04 (r-right c (replacePR.ri Pre))
-    ... | s-left _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ; ci = lift tt } where
-        repl09 : tree1 ≡ node key₂ v1 (node key₁ value₁ left right) tree₁
-        repl09 = si-property1 si
-        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
-        repl10 with si-property1 si
-        ... | refl = si
-        repl03 : child-replaced key (node key₁ value₁ left right) ≡ right
-        repl03 with <-cmp key key₁
-        ... | tri< a1 ¬b ¬c = ⊥-elim (¬c c)
-        ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
-        ... | tri> ¬a ¬b c = refl
-        repl02 : child-replaced key (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡ node key₁ value₁ left right
-        repl02 with repl09 | <-cmp key key₂
-        ... | refl | tri< a ¬b ¬c = refl
-        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬a lt)
-        ... | refl | tri> ¬a ¬b c = ⊥-elim (¬a lt)
-        repl04 : node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡ child-replaced key tree1
-        repl04  = begin
-            node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡⟨ cong (λ k → node key₁ value₁ left k ) repl03 ⟩
-            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
-            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
-            child-replaced key tree1 ∎  where open ≡-Reasoning
-        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ left repl)
-        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ left repl) ) repl04  (r-right c (replacePR.ri Pre))
-
-TerminatingLoopS : {l m : Level} {t : Set l} (Index : Set m ) → {Invraiant : Index → Set m } → ( reduce : Index → ℕ)
-   → (r : Index) → (p : Invraiant r)
-   → (loop : (r : Index)  → Invraiant r → (next : (r1 : Index)  → Invraiant r1 → reduce r1 < reduce r  → t ) → t) → t
-TerminatingLoopS {_} {_} {t} Index {Invraiant} reduce r p loop with <-cmp 0 (reduce r)
-... | tri≈ ¬a b ¬c = loop r p (λ r1 p1 lt → ⊥-elim (lemma3 b lt) )
-... | tri< a ¬b ¬c = loop r p (λ r1 p1 lt1 → TerminatingLoop1 (reduce r) r r1 (m≤n⇒m≤1+n lt1) p1 lt1 ) where
-    TerminatingLoop1 : (j : ℕ) → (r r1 : Index) → reduce r1 < suc j  → Invraiant r1 →  reduce r1 < reduce r → t
-    TerminatingLoop1 zero r r1 n≤j p1 lt = loop r1 p1 (λ r2 p1 lt1 → ⊥-elim (lemma5 n≤j lt1))
-    TerminatingLoop1 (suc j) r r1  n≤j p1 lt with <-cmp (reduce r1) (suc j)
-    ... | tri< a ¬b ¬c = TerminatingLoop1 j r r1 a p1 lt
-    ... | tri≈ ¬a b ¬c = loop r1 p1 (λ r2 p2 lt1 → TerminatingLoop1 j r1 r2 (subst (λ k → reduce r2 < k ) b lt1 ) p2 lt1 )
-    ... | tri> ¬a ¬b c =  ⊥-elim ( nat-≤> c n≤j )
-
 open _∧_
 
 ri-tr>  : {n : Level} {A : Set n}  → (tree repl : bt A) → (key key₁ : ℕ) → (value : A)
@@ -679,6 +434,337 @@
 -- RTtoTI1 (node key₁ value₁ (node key₂ value₂ n n₁) _) (node key₁ _ _ _) key value (t-node _ _ _ x₁ x₂ a b c d ti ti₁) (r-left x ri) =
 --     t-node _ _ _ (subst (λ k → k < key₁ ) (sym (rt-property-key ri)) x₁) x₂ ? ? c d (RTtoTI1 _ _ key value ti ri) ti₁ -- key₂ < key₁
 
+popStackInvariant : {n : Level} {A : Set n} → (rest : List ( bt A))
+           → ( tree parent orig : bt A) →  (key : ℕ)
+           → stackInvariant key tree  orig ( tree ∷ parent ∷ rest )
+           → stackInvariant key parent orig (parent ∷ rest )
+popStackInvariant rest tree parent orig key (s-right .tree .orig tree₁ x si) = sc00 where
+     sc00 : stackInvariant key parent orig (parent ∷ rest )
+     sc00 with si-property1 si
+     ... | refl = si
+popStackInvariant rest tree parent orig key (s-left .tree .orig tree₁ x si) = sc00 where
+     sc00 : stackInvariant key parent orig (parent ∷ rest )
+     sc00 with si-property1 si
+     ... | refl = si
+
+
+siToTreeinvariant : {n : Level} {A : Set n} → (rest : List ( bt A))
+           → ( tree orig : bt A) →  (key : ℕ)
+           → treeInvariant orig
+           → stackInvariant key tree  orig ( tree ∷ rest )
+           → treeInvariant tree
+siToTreeinvariant .[] tree .tree key ti s-nil = ti
+siToTreeinvariant .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-right .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ leaf (node key₁ _ _ _) ∷ []) .(node key₁ _ _ _) .(node _ _ leaf (node key₁ _ _ _)) key (t-right _ key₁ x₁ x₂ x₃ ti) (s-right .(node key₁ _ _ _) .(node _ _ leaf (node key₁ _ _ _)) .leaf x s-nil) = ti
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) leaf ∷ []) .leaf .(node _ _ (node key₁ _ _ _) leaf) key (t-left key₁ _ x₁ x₂ x₃ ti) (s-right .leaf .(node _ _ (node key₁ _ _ _) leaf) .(node key₁ _ _ _) x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _) ∷ []) .(node key₂ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) key (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node key₂ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key₁ _ _ _) x s-nil) = ti₁
+siToTreeinvariant .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-right .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ ti₁ = ti₁
+... | t-left key₁ _ x₂ x₃ x₄ ti₁ = t-leaf
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ ti₁ ti₂ = ti₂
+siToTreeinvariant .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-left .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ ti₁ = ti₁
+... | t-left key₁ _ x₂ x₃ x₄ ti₁ = t-leaf
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ ti₁ ti₂ = ti₂
+siToTreeinvariant .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-left .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ leaf (node key₁ _ _ _) ∷ []) .leaf .(node _ _ leaf (node key₁ _ _ _)) key (t-right _ key₁ x₁ x₂ x₃ ti) (s-left .leaf .(node _ _ leaf (node key₁ _ _ _)) .(node key₁ _ _ _) x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) leaf ∷ []) .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) leaf) key (t-left key₁ _ x₁ x₂ x₃ ti) (s-left .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) leaf) .leaf x s-nil) = ti
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _) ∷ []) .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) key (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-left .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key₂ _ _ _) x s-nil) = ti
+siToTreeinvariant .(node _ _ tree tree₁ ∷ _) tree orig key ti (s-left .tree .orig tree₁ x si2@(s-right .(node _ _ tree tree₁) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ t = t-leaf
+... | t-left key₁ _ x₂ x₃ x₄ t = t
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ t t₁ = t
+siToTreeinvariant .(node _ _ tree tree₁ ∷ _) tree orig key ti (s-left .tree .orig tree₁ x si2@(s-left .(node _ _ tree tree₁) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ t = t-leaf
+... | t-left key₁ _ x₂ x₃ x₄ t = t
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ t t₁ = t
+
+record replacePR {n : Level} {A : Set n} (key : ℕ) (value : A) (tree repl : bt A ) (stack : List (bt A)) (C : bt A → bt A → List (bt A) → Set n) : Set n where
+   field
+     tree0 : bt A
+     ti : treeInvariant tree0
+     si : stackInvariant key tree tree0 stack
+     ri : replacedTree key value (child-replaced key tree ) repl
+     rti : treeInvariant repl
+     ci : C tree repl stack     -- data continuation
+
+replaceNodeP : {n m : Level} {A : Set n} {t : Set m} → (key : ℕ) → (value : A) → (tree : bt A)
+    → (tree ≡ leaf ) ∨ ( node-key tree ≡ just key )
+    → (treeInvariant tree ) → ((tree1 : bt A) → treeInvariant tree1 →  replacedTree key value (child-replaced key tree) tree1 → t) → t
+replaceNodeP k v1 leaf C P next = next (node k v1 leaf leaf) (t-single k v1 ) r-leaf
+replaceNodeP k v1 (node .k value t t₁) (case2 refl) P next = next (node k v1 t t₁) (replaceTree1 k value v1 P)
+     (subst (λ j → replacedTree k v1 j  (node k v1 t t₁) ) repl00 r-node) where
+         repl00 : node k value t t₁ ≡ child-replaced k (node k value t t₁)
+         repl00 with <-cmp k k
+         ... | tri< a ¬b ¬c = ⊥-elim (¬b refl)
+         ... | tri≈ ¬a b ¬c = refl
+         ... | tri> ¬a ¬b c = ⊥-elim (¬b refl)
+
+
+replaceP : {n m : Level} {A : Set n} {t : Set m}
+     → (key : ℕ) → (value : A) → {tree : bt A} ( repl : bt A)
+     → (stack : List (bt A)) → replacePR key value tree repl stack (λ _ _ _ → Lift n ⊤)
+     → (next : ℕ → A → {tree1 : bt A } (repl : bt A) → (stack1 : List (bt A))
+         → replacePR key value tree1 repl stack1 (λ _ _ _ → Lift n ⊤) → length stack1 < length stack → t)
+     → (exit : (tree1 repl : bt A) → treeInvariant repl ∧ replacedTree key value tree1 repl → t) → t
+replaceP key value {tree}  repl [] Pre next exit = ⊥-elim ( si-property0 (replacePR.si Pre) refl ) -- can't happen
+replaceP key value {tree}  repl (leaf ∷ []) Pre next exit with  si-property-last  _ _ _ _  (replacePR.si Pre)-- tree0 ≡ leaf
+... | refl  =  exit (replacePR.tree0 Pre) (node key value leaf leaf) ⟪ t-single _ _  ,  r-leaf ⟫
+replaceP key value {tree}  repl (node key₁ value₁ left right ∷ []) Pre next exit with <-cmp key key₁
+... | tri< a ¬b ¬c = exit (replacePR.tree0 Pre) (node key₁ value₁ repl right )
+        ⟪ RTtoTI0 _ _ _ _ (replacePR.ti Pre) repl01 , repl01 ⟫ where
+    repl01 : replacedTree key value (replacePR.tree0 Pre) (node key₁ value₁ repl right )
+    repl01 with si-property1 (replacePR.si Pre) | si-property-last  _ _ _ _  (replacePR.si Pre)
+    repl01 | refl | refl = subst (λ k → replacedTree key value  (node key₁ value₁ k right ) (node key₁ value₁ repl right )) repl02 (r-left a repl03) where
+        repl03 : replacedTree key value ( child-replaced key (node key₁ value₁ left right)) repl
+        repl03 = replacePR.ri Pre
+        repl02 : child-replaced key (node key₁ value₁ left right) ≡ left
+        repl02 with <-cmp key key₁
+        ... | tri< a ¬b ¬c = refl
+        ... | tri≈ ¬a b ¬c = ⊥-elim ( ¬a a)
+        ... | tri> ¬a ¬b c = ⊥-elim ( ¬a a)
+... | tri≈ ¬a b ¬c = exit (replacePR.tree0 Pre) repl ⟪  RTtoTI0 _ _ _ _ (replacePR.ti Pre) repl01 , repl01 ⟫ where
+    repl01 : replacedTree key value (replacePR.tree0 Pre) repl
+    repl01 with si-property1 (replacePR.si Pre) | si-property-last  _ _ _ _  (replacePR.si Pre)
+    repl01 | refl | refl = subst (λ k → replacedTree key value k repl) repl02 (replacePR.ri Pre) where
+        repl02 : child-replaced key (node key₁ value₁ left right) ≡ node key₁ value₁ left right
+        repl02 with <-cmp key key₁
+        ... | tri< a ¬b ¬c = ⊥-elim ( ¬b b)
+        ... | tri≈ ¬a b ¬c = refl
+        ... | tri> ¬a ¬b c = ⊥-elim ( ¬b b)
+... | tri> ¬a ¬b c = exit (replacePR.tree0 Pre) (node key₁ value₁ left repl  ) ⟪  RTtoTI0 _ _ _ _ (replacePR.ti Pre) repl01 , repl01 ⟫ where
+    repl01 : replacedTree key value (replacePR.tree0 Pre) (node key₁ value₁ left repl )
+    repl01 with si-property1 (replacePR.si Pre) | si-property-last  _ _ _ _  (replacePR.si Pre)
+    repl01 | refl | refl = subst (λ k → replacedTree key value  (node key₁ value₁ left k ) (node key₁ value₁ left repl )) repl02 (r-right c repl03) where
+        repl03 : replacedTree key value ( child-replaced key (node key₁ value₁ left right)) repl
+        repl03 = replacePR.ri Pre
+        repl02 : child-replaced key (node key₁ value₁ left right) ≡ right
+        repl02 with <-cmp key key₁
+        ... | tri< a ¬b ¬c = ⊥-elim ( ¬c c)
+        ... | tri≈ ¬a b ¬c = ⊥-elim ( ¬c c)
+        ... | tri> ¬a ¬b c = refl
+replaceP {n} {_} {A} key value  {tree}  repl (leaf ∷ st@(tree1 ∷ st1)) Pre next exit = next key value repl st Post ≤-refl where
+    Post :  replacePR key value tree1 repl (tree1 ∷ st1) (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ri = repl12 ;
+           rti = replacePR.rti Pre ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ leaf
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 tree₁ leaf) ≡ leaf
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = ⊥-elim (¬c x)
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬c x)
+        ... |  tri> ¬a ¬b c = refl
+        repl12 : replacedTree key value (child-replaced key  tree1  ) repl
+        repl12 = subst₂ (λ j k → replacedTree key value j k ) (sym (subst (λ k → child-replaced key k ≡ leaf) (sym repl09) repl07 ) ) (sym (rt-property-leaf (replacePR.ri Pre))) r-leaf
+    ... | s-left  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; rti = replacePR.rti Pre ; ri = repl12 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 leaf tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 leaf tree₁ ) ≡ leaf
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = refl
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬a x)
+        ... |  tri> ¬a ¬b c = ⊥-elim (¬a x)
+        repl12 : replacedTree key value (child-replaced key  tree1  ) repl
+        repl12 = subst₂ (λ j k → replacedTree key value j k ) (sym (subst (λ k → child-replaced key k ≡ leaf) (sym repl09) repl07) ) (sym (rt-property-leaf (replacePR.ri Pre ))) r-leaf
+replaceP {n} {_} {A} key value {tree}  repl (node key₁ value₁ left right ∷ st@(tree1 ∷ st1)) Pre next exit  with <-cmp key key₁
+... | tri< a ¬b ¬c = next key value (node key₁ value₁ repl right ) st Post ≤-refl where
+    Post : replacePR key value tree1 (node key₁ value₁ repl right ) st (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10
+      ; rti = repl13
+      ; ri = repl12 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ (node key₁ value₁ left right)
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl11 : stackInvariant key (node key₂ v1 tree₁ (node key₁ value₁ left right)) (replacePR.tree0 Pre) (node key₂ v1 tree₁ (node key₁ value₁ left right)∷ st1)
+        repl11 = subst (λ k → stackInvariant key k (replacePR.tree0 Pre) (k ∷ st1)) repl09 repl10
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ left
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = refl
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
+        ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
+        repl02 : child-replaced key (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri> ¬a ¬b c = refl
+        repl04 : node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡⟨ cong (λ k → node key₁ value₁ k right) repl03  ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl05 : node key₁ value₁ left right ≡ child-replaced key tree1
+        repl05  = begin
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ repl right)
+        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ repl right) ) repl04  (r-left a (replacePR.ri Pre))
+        repl13 : treeInvariant (node key₁ value₁ repl right)
+        repl13 = RTtoTI0 _ _ _ _ (subst (λ k → treeInvariant k) repl05 (treeRightDown _ _ (siToTreeinvariant _ _ _ _ (replacePR.ti Pre) repl11 ) )) repl12
+    ... | s-left _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; rti = repl13 ; ri = repl12 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 (node key₁ value₁ left right) tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ left
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = refl
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
+        ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
+        repl02 : child-replaced key (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = refl
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬a lt)
+        ... | refl | tri> ¬a ¬b c = ⊥-elim (¬a lt)
+        repl04 : node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡⟨ cong (λ k → node key₁ value₁ k right) repl03  ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl05 : node key₁ value₁ left right ≡ child-replaced key tree1
+        repl05  = begin
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ repl right)
+        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ repl right) ) repl04  (r-left a (replacePR.ri Pre))
+        repl11 = subst (λ k → stackInvariant key k (replacePR.tree0 Pre) (k ∷ st1)) repl09 repl10
+        repl13 :  treeInvariant (node key₁ value₁ repl right)
+        repl13 = RTtoTI0 _ _ _ _ (subst (λ k → treeInvariant k) repl05 (treeLeftDown _ _ (siToTreeinvariant _ _ _ _ (replacePR.ti Pre) repl11 ) )) repl12
+... | tri≈ ¬a b ¬c = next key value (node key₁ value  left right ) st Post ≤-refl where
+    Post :  replacePR key value tree1 (node key₁ value left right ) (tree1 ∷ st1) (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; rti = repl13 ; ri = repl12 b ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ tree -- (node key₁ value₁  left right)
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 tree₁ tree) ≡ tree
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = ⊥-elim (¬c x)
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬c x)
+        ... |  tri> ¬a ¬b c = refl
+        repl12 : (key ≡ key₁) → replacedTree key value (child-replaced key  tree1  ) (node key₁ value left right )
+        repl12 refl with repl09
+        ... | refl = subst (λ k → replacedTree key value k (node key₁ value left right )) (sym repl07) r-node
+        repl13 : treeInvariant (node key₁ value left right)
+        repl13 = RTtoTI0 _ _ _ _ (siToTreeinvariant _ _ _ _ (replacePR.ti Pre) (replacePR.si Pre))  r-node
+    ... | s-left  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; rti = repl13 ; ri = repl12 b ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 tree tree₁ ) ≡ tree
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = refl
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬a x)
+        ... |  tri> ¬a ¬b c = ⊥-elim (¬a x)
+        repl12 : (key ≡ key₁) → replacedTree key value (child-replaced key  tree1  ) (node key₁ value left right )
+        repl12 refl with repl09
+        ... | refl = subst (λ k → replacedTree key value k (node key₁ value left right )) (sym repl07) r-node
+        repl13 : treeInvariant (node key₁ value left right)
+        repl13 = RTtoTI0 _ _ _ _ (siToTreeinvariant _ _ _ _ (replacePR.ti Pre) (replacePR.si Pre))  r-node
+... | tri> ¬a ¬b c = next key value (node key₁ value₁ left repl ) st Post ≤-refl where
+    Post : replacePR key value tree1 (node key₁ value₁ left repl ) st (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; rti = repl13 ; ri = repl12 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ (node key₁ value₁ left right)
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ right
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = ⊥-elim (¬c c)
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
+        ... | tri> ¬a ¬b c = refl
+        repl02 : child-replaced key (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri> ¬a ¬b c = refl
+        repl04 : node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡⟨ cong (λ k → node key₁ value₁ left k ) repl03 ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl05 : node key₁ value₁ left right ≡ child-replaced key tree1
+        repl05  = begin
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ left repl)
+        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ left repl) ) repl04 (r-right c (replacePR.ri Pre))
+        repl11 = subst (λ k → stackInvariant key k (replacePR.tree0 Pre) (k ∷ st1)) repl09 repl10
+        repl13 : treeInvariant (node key₁ value₁ left repl)
+        repl13 = RTtoTI0 _ _ _ _ (subst (λ k → treeInvariant k) repl05 (treeRightDown _ _ (siToTreeinvariant _ _ _ _ (replacePR.ti Pre) repl11 ) )) repl12
+    ... | s-left _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; rti = repl13 ; ri = repl12 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 (node key₁ value₁ left right) tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ right
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = ⊥-elim (¬c c)
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
+        ... | tri> ¬a ¬b c = refl
+        repl02 : child-replaced key (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = refl
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬a lt)
+        ... | refl | tri> ¬a ¬b c = ⊥-elim (¬a lt)
+        repl04 : node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡⟨ cong (λ k → node key₁ value₁ left k ) repl03 ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl05 : node key₁ value₁ left right ≡ child-replaced key tree1
+        repl05  = begin
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+        repl12 : replacedTree key value (child-replaced key  tree1  ) (node key₁ value₁ left repl)
+        repl12 = subst (λ k → replacedTree key value k (node key₁ value₁ left repl) ) repl04  (r-right c (replacePR.ri Pre))
+        repl13 : treeInvariant (node key₁ value₁ left repl)
+        repl13 = RTtoTI0 _ _ _ _ (subst (λ k → treeInvariant k) repl05 (treeLeftDown _ _
+           (siToTreeinvariant _ _ _ _ (replacePR.ti Pre) (subst (λ k → stackInvariant key k (replacePR.tree0 Pre) (k ∷ st1)) repl09 repl10)) )) repl12
+
+TerminatingLoopS : {l m : Level} {t : Set l} (Index : Set m ) → {Invraiant : Index → Set m } → ( reduce : Index → ℕ)
+   → (r : Index) → (p : Invraiant r)
+   → (loop : (r : Index)  → Invraiant r → (next : (r1 : Index)  → Invraiant r1 → reduce r1 < reduce r  → t ) → t) → t
+TerminatingLoopS {_} {_} {t} Index {Invraiant} reduce r p loop with <-cmp 0 (reduce r)
+... | tri≈ ¬a b ¬c = loop r p (λ r1 p1 lt → ⊥-elim (lemma3 b lt) )
+... | tri< a ¬b ¬c = loop r p (λ r1 p1 lt1 → TerminatingLoop1 (reduce r) r r1 (m≤n⇒m≤1+n lt1) p1 lt1 ) where
+    TerminatingLoop1 : (j : ℕ) → (r r1 : Index) → reduce r1 < suc j  → Invraiant r1 →  reduce r1 < reduce r → t
+    TerminatingLoop1 zero r r1 n≤j p1 lt = loop r1 p1 (λ r2 p1 lt1 → ⊥-elim (lemma5 n≤j lt1))
+    TerminatingLoop1 (suc j) r r1  n≤j p1 lt with <-cmp (reduce r1) (suc j)
+    ... | tri< a ¬b ¬c = TerminatingLoop1 j r r1 a p1 lt
+    ... | tri≈ ¬a b ¬c = loop r1 p1 (λ r2 p2 lt1 → TerminatingLoop1 j r1 r2 (subst (λ k → reduce r2 < k ) b lt1 ) p2 lt1 )
+    ... | tri> ¬a ¬b c =  ⊥-elim ( nat-≤> c n≤j )
+
+
 insertTreeP : {n m : Level} {A : Set n} {t : Set m} → (tree : bt A) → (key : ℕ) → (value : A) → treeInvariant tree
      → (exit : (tree repl : bt A) → treeInvariant repl ∧ replacedTree key value tree repl → t ) → t
 insertTreeP {n} {m} {A} {t} tree key value P0 exit =
@@ -687,16 +773,17 @@
        $ λ t s P C → replaceNodeP key value t C (proj1 P)
        $ λ t1 P1 R → TerminatingLoopS (List (bt A) ∧ bt A ∧ bt A )
             {λ p → replacePR key value  (proj1 (proj2 p)) (proj2 (proj2 p)) (proj1 p)  (λ _ _ _ → Lift n ⊤ ) }
-               (λ p → length (proj1 p)) ⟪ s , ⟪ t , t1 ⟫ ⟫ record { tree0 = tree ; ti = P0 ; si = proj2 P ; ri = R ; ci = lift tt }
+               (λ p → length (proj1 p)) ⟪ s , ⟪ t , t1 ⟫ ⟫ record { tree0 = tree ; ti = P0 ; si = proj2 P ; rti = P1 ; ri = R ; ci = lift tt }
        $  λ p P1 loop → replaceP key value  (proj2 (proj2 p)) (proj1 p) P1
             (λ key value {tree1} repl1 stack P2 lt → loop ⟪ stack , ⟪ tree1 , repl1  ⟫ ⟫ P2 lt )
-       $ λ tree repl P → exit tree repl ⟪ RTtoTI0 _ _ _ _ (proj1 P) (proj2 P) , proj2 P ⟫
+       $ λ tree repl P → exit tree repl P
 
 insertTestP1 = insertTreeP leaf 1 1 t-leaf
   $ λ _ x0 P0 → insertTreeP x0 2 1 (proj1 P0)
   $ λ _ x1 P1 → insertTreeP x1 3 2 (proj1 P1)
   $ λ _ x2 P2 → insertTreeP x2 2 2 (proj1 P2) (λ _ x P  → x )
 
+
 top-value : {n : Level} {A : Set n} → (tree : bt A) →  Maybe A
 top-value leaf = nothing
 top-value (node key value tree tree₁) = just value
@@ -972,6 +1059,7 @@
        origrb : RBtreeInvariant orig
        treerb : RBtreeInvariant tree     -- tree node te be replaced
        replrb : RBtreeInvariant repl
+       replti : treeInvariant repl
        si : stackInvariant key tree orig stack
        state : RBI-state key value tree repl stack
 
@@ -1774,54 +1862,6 @@
 ... | s2-s12p _ refl refl = ⟪ (λ () ) , ( λ () ) ⟫
 ... | s2-1s2p _ refl refl = ⟪ (λ () ) , ( λ () ) ⟫
 
-popStackInvariant : {n : Level} {A : Set n} → (rest : List ( bt (Color ∧ A)))
-           → ( tree parent orig : bt (Color ∧ A)) →  (key : ℕ)
-           → stackInvariant key tree  orig ( tree ∷ parent ∷ rest )
-           → stackInvariant key parent orig (parent ∷ rest )
-popStackInvariant rest tree parent orig key (s-right .tree .orig tree₁ x si) = sc00 where
-     sc00 : stackInvariant key parent orig (parent ∷ rest )
-     sc00 with si-property1 si
-     ... | refl = si
-popStackInvariant rest tree parent orig key (s-left .tree .orig tree₁ x si) = sc00 where
-     sc00 : stackInvariant key parent orig (parent ∷ rest )
-     sc00 with si-property1 si
-     ... | refl = si
-
-
-siToTreeinvariant : {n : Level} {A : Set n} → (rest : List ( bt (Color ∧ A)))
-           → ( tree orig : bt (Color ∧ A)) →  (key : ℕ)
-           → treeInvariant orig
-           → stackInvariant key tree  orig ( tree ∷ rest )
-           → treeInvariant tree
-siToTreeinvariant .[] tree .tree key ti s-nil = ti
-siToTreeinvariant .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-right .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
-siToTreeinvariant .(node _ _ leaf (node key₁ _ _ _) ∷ []) .(node key₁ _ _ _) .(node _ _ leaf (node key₁ _ _ _)) key (t-right _ key₁ x₁ x₂ x₃ ti) (s-right .(node key₁ _ _ _) .(node _ _ leaf (node key₁ _ _ _)) .leaf x s-nil) = ti
-siToTreeinvariant .(node _ _ (node key₁ _ _ _) leaf ∷ []) .leaf .(node _ _ (node key₁ _ _ _) leaf) key (t-left key₁ _ x₁ x₂ x₃ ti) (s-right .leaf .(node _ _ (node key₁ _ _ _) leaf) .(node key₁ _ _ _) x s-nil) = t-leaf
-siToTreeinvariant .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _) ∷ []) .(node key₂ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) key (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node key₂ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key₁ _ _ _) x s-nil) = ti₁
-siToTreeinvariant .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-right .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
-... | t-single _ _ = t-leaf
-... | t-right _ key₁ x₂ x₃ x₄ ti₁ = ti₁
-... | t-left key₁ _ x₂ x₃ x₄ ti₁ = t-leaf
-... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ ti₁ ti₂ = ti₂
-siToTreeinvariant .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-left .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
-... | t-single _ _ = t-leaf
-... | t-right _ key₁ x₂ x₃ x₄ ti₁ = ti₁
-... | t-left key₁ _ x₂ x₃ x₄ ti₁ = t-leaf
-... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ ti₁ ti₂ = ti₂
-siToTreeinvariant .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-left .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
-siToTreeinvariant .(node _ _ leaf (node key₁ _ _ _) ∷ []) .leaf .(node _ _ leaf (node key₁ _ _ _)) key (t-right _ key₁ x₁ x₂ x₃ ti) (s-left .leaf .(node _ _ leaf (node key₁ _ _ _)) .(node key₁ _ _ _) x s-nil) = t-leaf
-siToTreeinvariant .(node _ _ (node key₁ _ _ _) leaf ∷ []) .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) leaf) key (t-left key₁ _ x₁ x₂ x₃ ti) (s-left .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) leaf) .leaf x s-nil) = ti
-siToTreeinvariant .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _) ∷ []) .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) key (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-left .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key₂ _ _ _) x s-nil) = ti
-siToTreeinvariant .(node _ _ tree tree₁ ∷ _) tree orig key ti (s-left .tree .orig tree₁ x si2@(s-right .(node _ _ tree tree₁) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
-... | t-single _ _ = t-leaf
-... | t-right _ key₁ x₂ x₃ x₄ t = t-leaf
-... | t-left key₁ _ x₂ x₃ x₄ t = t
-... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ t t₁ = t
-siToTreeinvariant .(node _ _ tree tree₁ ∷ _) tree orig key ti (s-left .tree .orig tree₁ x si2@(s-left .(node _ _ tree tree₁) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
-... | t-single _ _ = t-leaf
-... | t-right _ key₁ x₂ x₃ x₄ t = t-leaf
-... | t-left key₁ _ x₂ x₃ x₄ t = t
-... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ t t₁ = t
 
 PGtoRBinvariant1 : {n : Level} {A : Set n}
            → (tree orig : bt (Color ∧ A) )
@@ -1866,6 +1906,7 @@
          ; origrb = rbi
          ; treerb = rb-leaf
          ; replrb = rb-red key value refl refl refl rb-leaf rb-leaf
+         ; replti = t-single _ _
          ; si = subst (λ k → stackInvariant key k leaf _ ) crbt01 si
          ; state = rotate leaf refl rbr-leaf
          } where
@@ -1882,6 +1923,7 @@
          ; origrb = rbi
          ; treerb = rbi
          ; replrb = crbt03 value₁ rbi
+         ; replti = RTtoTI0 _ _ _ _ (siToTreeinvariant _ _ _ _ ti si) r-node
          ; si = si
          ; state = rebuild refl (crbt01 value₁ ) (λ ()) crbt04
          }  where
@@ -1905,6 +1947,7 @@
          ; origrb = rbi
          ; treerb = rb-leaf
          ; replrb = rb-red key value refl refl refl rb-leaf rb-leaf
+         ; replti = t-single _ _
          ; si = si
          ; state = rotate leaf refl rbr-leaf
          }
@@ -1917,6 +1960,7 @@
          ; origrb = rbi
          ; treerb = treerb
          ; replrb = crbt03 value₁ treerb
+         ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ ti (subst (λ k → stackInvariant _ _ orig (k ∷ _)) eq2 si )) crbt04
          ; si = si
          ; state = rebuild refl (crbt01 value₁ ) (λ ()) crbt04
          }  where
@@ -1933,6 +1977,14 @@
              treerb : RBtreeInvariant (node key₁ value₁ left right)
              treerb = PGtoRBinvariant1 _ orig rbi _ si
 
+
+ti-to-black : {n : Level} {A : Set n} → {tree : bt (Color ∧ A)} → treeInvariant tree → treeInvariant (to-black tree)
+ti-to-black {n} {A} {.leaf} t-leaf = t-leaf
+ti-to-black {n} {A} {.(node key value leaf leaf)} (t-single key value) = t-single key ⟪ Black , proj2 value ⟫
+ti-to-black {n} {A} {.(node key _ leaf (node key₁ _ _ _))} (t-right key key₁ x x₁ x₂ ti) = t-right key key₁ x x₁ x₂ ti
+ti-to-black {n} {A} {.(node key₁ _ (node key _ _ _) leaf)} (t-left key key₁ x x₁ x₂ ti) = t-left key key₁ x x₁ x₂ ti
+ti-to-black {n} {A} {.(node key₁ _ (node key _ _ _) (node key₂ _ _ _))} (t-node key key₁ key₂ x x₁ x₂ x₃ x₄ x₅ ti ti₁) = t-node key key₁ key₂ x x₁ x₂ x₃ x₄ x₅ ti ti₁
+
 --
 --   rotate and rebuild replaceTree and rb-invariant
 --
@@ -1994,9 +2046,12 @@
          ; origrb = RBI.origrb r
          ; treerb = RBI.origrb r
          ; replrb = rb08 cc
+         ; replti = RB-repl→ti _ _ _ _ (RBI.origti r) rb10
          ; si = s-nil
-         ; state = top-black  refl (case1 (rbr-left (trans (cong color (rb04 si eq refl)) cc) a (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)))
-         }
+         ; state = top-black  refl (case1 rb10 )
+         } where
+             rb10 : replacedRBTree key value (node key₁ value₁ left right) (node key₁ value₁ repl right)
+             rb10 = rbr-left (trans (cong color (rb04 si eq refl)) cc) a (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)
        rb07 (case1 repl-red) = exit  (orig ∷ []) refl record {
          tree = orig
          ; repl = to-black (node key₁ value₁ repl right)
@@ -2004,9 +2059,13 @@
          ; origrb = RBI.origrb r
          ; treerb = RBI.origrb r
          ; replrb = rb-black _ _ rb06 (RBI.replrb r) (RBtreeRightDown _ _ (RBI.origrb r))
+         ; replti = RB-repl→ti _ _ _ _ (ti-to-black (RBI.origti r)) rb10
          ; si = s-nil
-         ; state = top-black  refl (case2 (rbr-black-left repl-red a (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)))
-         }
+         ; state = top-black  refl (case2 rb10 )
+         } where
+              rb10 : replacedRBTree key value (node key₁ ⟪ Black , proj2 value₁ ⟫ left right) (node key₁ ⟪ Black , proj2 value₁ ⟫ repl right)
+              rb10 = rbr-black-left repl-red a (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)
+
     ... | tri≈ ¬a b ¬c = ⊥-elim ( si-property-pne _ _ stack eq si b ) -- can't happen
     ... | tri> ¬a ¬b c = rb07 col where
        rb04 : stackInvariant key (RBI.tree r) orig stack → stack ≡ RBI.tree r ∷ orig ∷ [] → tr0 ≡ orig → right ≡ RBI.tree r
@@ -2037,9 +2096,11 @@
          ; origrb = RBI.origrb r
          ; treerb = RBI.origrb r
          ; replrb = rb08 cc
+         ; replti = RB-repl→ti _ _ _ _ (RBI.origti r) rb10
          ; si = s-nil
-         ; state = top-black  refl (case1 (rbr-right (trans (cong color (rb04 si eq refl)) cc) c (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)))
-         }
+         ; state = top-black  refl (case1 rb10)
+         } where
+             rb10 = rbr-right (trans (cong color (rb04 si eq refl)) cc) c (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)
        rb07 (case1 repl-red ) = exit  (orig ∷ [])  refl record {
          tree = orig
          ; repl = to-black (node key₁ value₁ left repl)
@@ -2047,9 +2108,11 @@
          ; origrb = RBI.origrb r
          ; treerb = RBI.origrb r
          ; replrb = rb-black _ _ (sym rb06) (RBtreeLeftDown _ _ (RBI.origrb r)) (RBI.replrb r)
+         ; replti = RB-repl→ti _ _ _ _ (ti-to-black (RBI.origti r)) rb10
          ; si = s-nil
-         ; state = top-black refl (case2 (rbr-black-right repl-red c (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)))
-         }
+         ; state = top-black refl (case2 rb10 )
+         } where
+            rb10 = rbr-black-right repl-red c (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot)
     rebuildCase : (ceq : color (RBI.tree r) ≡ color repl)
        → (bdepth-eq : black-depth repl ≡ black-depth (RBI.tree r))
        → (¬ RBI.tree r ≡ leaf)
@@ -2077,6 +2140,7 @@
               ; origrb = RBI.origrb r
               ; treerb = treerb pg
               ; replrb = rb02
+              ; replti = RB-repl→ti _ _ _ _ (rb08 pg) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-left ceq rb04 rot))
               ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
               ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))  (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-left ceq rb04 rot))
              } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
@@ -2106,6 +2170,7 @@
               ; origrb = RBI.origrb r
               ; treerb = treerb pg
               ; replrb = rb02
+              ; replti = RB-repl→ti _ _ _ _ (rb08 pg) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-right ceq rb04 rot))
               ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
               ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-right ceq rb04 rot))
              } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
@@ -2135,6 +2200,7 @@
               ; origrb = RBI.origrb r
               ; treerb = treerb pg
               ; replrb = rb02
+              ; replti = RB-repl→ti _ _ _ _ (rb08 pg) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-left ceq rb04 rot))
               ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
               ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-left ceq rb04 rot))
              } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
@@ -2164,6 +2230,7 @@
               ; origrb = RBI.origrb r
               ; treerb = treerb pg
               ; replrb = rb02
+              ; replti = RB-repl→ti _ _ _ _ (rb08 pg) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-right ceq rb04 rot))
               ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
               ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → replacedRBTree key value k rb01) (sym x) (rbr-right ceq rb04 rot))
              } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
@@ -2222,6 +2289,7 @@
             ; origrb = RBI.origrb r
             ; treerb = rb02
             ; replrb = subst (λ k → RBtreeInvariant k) rb10 (rb-black _ _ rb18 (RBI.replrb r) (rb-red _ _ rb16 uncle-black rb19 rb06 rb05))
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb11
             ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
             ; state = rebuild (trans (cong color x₁) (cong proj1 (sym rb14))) rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) rb11
            } rb15 where
@@ -2290,6 +2358,7 @@
             ; origrb = RBI.origrb r
             ; treerb = rb02
             ; replrb = rb10
+            ; replti =  RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb11
             ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
             ; state = rebuild rb33 rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) rb11
            } rb15 where
@@ -2396,6 +2465,7 @@
             ; origrb = RBI.origrb r
             ; treerb = rb02
             ; replrb = rb10
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb11
             ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
             ; state = rebuild rb33 rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) rb11
            } rb15 where
@@ -2507,6 +2577,7 @@
             ; origrb = RBI.origrb r
             ; treerb = rb02
             ; replrb = subst (λ k → RBtreeInvariant k) rb10 (rb-black _ _ rb18 (rb-red _ _ uncle-black rb16 rb19 rb05 rb06) (RBI.replrb r) )
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb11
             ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
             ; state = rebuild rb33 rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) rb11
            } rb15 where
@@ -2594,9 +2665,9 @@
             ; origrb = RBI.origrb r
             ; treerb = treerb pg
             ; replrb = rb06
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (rb00 pg))) rb11
             ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
-            ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
-                (subst (λ k → replacedRBTree key value k (node kp vp repl n1) ) (sym x) (rb02 rb04 ))
+            ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) rb11
            } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
             rb01 : bt (Color ∧ A)
             rb01 = node kp vp repl n1
@@ -2623,6 +2694,7 @@
             rb06 : RBtreeInvariant rb01
             rb06 = subst (λ k → RBtreeInvariant (node kp k repl n1))  rb04
                ( rb-black _ _ rb07 (RBI.replrb r) (RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))))
+            rb11 = subst (λ k → replacedRBTree key value k (node kp vp repl n1) ) (sym x) (rb02 rb04 )
        ... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
             tree = PG.parent pg
             ; repl = rb01
@@ -2630,6 +2702,7 @@
             ; origrb = RBI.origrb r
             ; treerb = treerb pg
             ; replrb = rb06
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (rb00 pg))) rb11
             ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
             ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
                 (subst (λ k → replacedRBTree key value k (node kp vp n1 repl) ) (sym x) (rb02 rb04 ))
@@ -2661,6 +2734,7 @@
             rb06 : RBtreeInvariant rb01
             rb06 = subst (λ k → RBtreeInvariant (node kp k n1 repl ))  rb04
                ( rb-black _ _ (sym rb07) (RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))) (RBI.replrb r) )
+            rb11 = subst (λ k → replacedRBTree key value k (node kp vp n1 repl) ) (sym x) (rb02 rb04 )
        insertCase1 | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
             tree = PG.parent pg
             ; repl = rb01
@@ -2668,9 +2742,10 @@
             ; origrb = RBI.origrb r
             ; treerb = treerb pg
             ; replrb = rb06
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (rb00 pg))) rb11
             ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
             ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
-                (subst (λ k → replacedRBTree key value k (node kp vp repl n1) ) (sym x) (rb02 rb04 ))
+                rb11
            } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
             rb01 : bt (Color ∧ A)
             rb01 = node kp vp repl n1
@@ -2697,6 +2772,7 @@
             rb06 : RBtreeInvariant rb01
             rb06 = subst (λ k → RBtreeInvariant (node kp k repl n1))  rb04
                ( rb-black _ _ rb07 (RBI.replrb r) (RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))))
+            rb11 = (subst (λ k → replacedRBTree key value k (node kp vp repl n1) ) (sym x) (rb02 rb04 ))
        insertCase1 | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
             tree = PG.parent pg
             ; repl = rb01
@@ -2704,9 +2780,10 @@
             ; origrb = RBI.origrb r
             ; treerb = treerb pg
             ; replrb = rb06
+            ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (rb00 pg))) rb11
             ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
             ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
-                (subst (λ k → replacedRBTree key value k (node kp vp n1 repl) ) (sym x) (rb02 rb04 ))
+              rb11
            } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
                 -- x   : PG.parent pg ≡ node kp vp (RBI.tree r) n1
                 -- x₁  : PG.grand pg ≡ node kg vg (PG.uncle pg) (PG.parent pg)
@@ -2735,6 +2812,7 @@
             rb06 : RBtreeInvariant rb01
             rb06 = subst (λ k → RBtreeInvariant (node kp k n1 repl ))  rb04
                ( rb-black _ _ (sym rb07) (RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))) (RBI.replrb r) )
+            rb11 =   (subst (λ k → replacedRBTree key value k (node kp vp n1 repl) ) (sym x) (rb02 rb04 ))
     ... | Red with PG.uncle pg in uneq
     ... | leaf = insertCase5 repl refl pg rot repl-red (cong color uneq) pcolor
     ... | node key₁ ⟪ Black , value₁ ⟫ t₁ t₂ = insertCase5 repl refl pg rot repl-red (cong color uneq) pcolor
@@ -2749,8 +2827,9 @@
                  ; origrb = RBI.origrb r
                  ; treerb = rb01
                  ; replrb = rb-red _ _ refl (RBtreeToBlackColor _ rb02) rb12 (rb-black _ _ rb13 (RBI.replrb r) rb04) (RBtreeToBlack _ rb02)
+                 ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb20
                  ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
-                 ; state = rotate _ refl (subst₂ (λ j k → replacedRBTree key value j k ) (sym rb09) refl  (rbr-flip-ll repl-red (rb05 refl uneq) rb06 rot))
+                 ; state = rotate _ refl rb20
              }  rb15 where
                rb00 : stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
                rb00 = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
@@ -2805,6 +2884,7 @@
                   length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
                   length stack ∎
                      where open ≤-Reasoning
+               rb20 = (subst₂ (λ j k → replacedRBTree key value j k ) (sym rb09) refl (rbr-flip-ll repl-red (rb05 refl uneq) rb06 rot))
     ... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
         insertCase2 : t
         insertCase2 = next  (PG.grand pg ∷ (PG.rest pg))
@@ -2815,7 +2895,8 @@
                  ; origrb = RBI.origrb r
                  ; treerb = rb01
                  ; replrb = rb-red _ _ refl (RBtreeToBlackColor _ rb02) rb12 (rb-black _ _ (sym rb13) rb04 (RBI.replrb r)) (RBtreeToBlack _ rb02)
-                  ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+                 ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb20
+                 ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
                  ; state = rotate _ refl (subst₂ (λ j k → replacedRBTree key value j k ) rb09 refl (rbr-flip-lr repl-red (rb05 refl uneq) rb06 rb21 rot))
              }  rb15 where
                --
@@ -2880,6 +2961,7 @@
                   length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
                   length stack ∎
                      where open ≤-Reasoning
+               rb20 = subst₂ (λ j k → replacedRBTree key value j k ) rb09 refl (rbr-flip-lr repl-red (rb05 refl uneq) rb06 rb21 rot)
     ... | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
         insertCase2 : t
         insertCase2 = next  (PG.grand pg ∷ (PG.rest pg))
@@ -2891,6 +2973,7 @@
                  ; treerb = rb01
                  ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
                  ; replrb = rb-red _ _ (RBtreeToBlackColor _ rb02) refl rb12 (RBtreeToBlack _ rb02) (rb-black _ _ rb13 (RBI.replrb r) rb04)
+                 ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb20
                  ; state = rotate _ refl (subst₂ (λ j k → replacedRBTree key value j k ) rb09 refl  (rbr-flip-rl repl-red (rb05 refl uneq) rb21 rb06 rot))
              }  rb15 where
                  -- x   : PG.parent pg ≡ node kp vp (RBI.tree r) n1
@@ -2961,6 +3044,7 @@
                   length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
                   length stack ∎
                      where open ≤-Reasoning
+               rb20 = subst₂ (λ j k → replacedRBTree key value j k ) rb09 refl  (rbr-flip-rl repl-red (rb05 refl uneq) rb21 rb06 rot)
     ... | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
            --- lt : kp < key
            --- x  : PG.parent pg ≡ node kp vp n1 (RBI.tree r)
@@ -2974,6 +3058,7 @@
                  ; origrb = RBI.origrb r
                  ; treerb = rb01
                  ; replrb = rb-red _ _ (RBtreeToBlackColor _ rb02) refl rb12  (RBtreeToBlack _ rb02) (rb-black _ _ (sym rb13) rb04 (RBI.replrb r) )
+                 ; replti = RB-repl→ti _ _ _ _  (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))) rb20
                  ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
                  ; state = rotate _ refl (subst₂ (λ j k → replacedRBTree key value j k ) (sym rb09) refl  (rbr-flip-rr repl-red (rb05 refl uneq) rb06 rot))
              }  rb15 where
@@ -3031,6 +3116,8 @@
                   length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
                   length stack ∎
                      where open ≤-Reasoning
+               rb20 = subst₂ (λ j k → replacedRBTree key value j k ) (sym rb09) refl  (rbr-flip-rr repl-red (rb05 refl uneq) rb06 rot)
+
 
 
 insertRBTreeP : {n m : Level} {A : Set n} {t : Set m} → (tree : bt (Color ∧ A)) → (key : ℕ) → (value : A)
@@ -3044,3 +3131,11 @@
           (λ stack  → length stack ) st rbi
             $ λ stack rbi replaceLoop → replaceRBP key value orig stack rbi (λ stack1 rbi1 lt → replaceLoop stack1 rbi1 lt )
             $ λ stack eq r → exit stack eq r
+
+
+insertRBTestP1 = insertRBTreeP leaf 1 1 t-leaf rb-leaf
+   $ λ _ x0 P0 → insertRBTreeP (RBI.repl P0) 2 1 (RBI.replti P0) (RBI.replrb P0)
+   $ λ _ x0 P0 → insertRBTreeP (RBI.repl P0) 3 2 (RBI.replti P0) (RBI.replrb P0)
+   $ λ _ x0 P0 → insertRBTreeP (RBI.repl P0) 2 2 (RBI.replti P0) (RBI.replrb P0)
+   $ λ _ x P  → RBI.repl P0
+
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RBTree0.agda	Sat Jul 20 17:01:50 2024 +0900
@@ -0,0 +1,1981 @@
+module RBTree0 where
+
+open import Level hiding (suc ; zero ; _⊔_ )
+
+open import Data.Nat hiding (compare)
+open import Data.Nat.Properties as NatProp
+open import Data.Maybe
+-- open import Data.Maybe.Properties
+open import Data.Empty
+open import Data.List
+open import Data.Product
+
+open import Function as F hiding (const)
+
+open import Relation.Binary
+open import Relation.Binary.PropositionalEquality
+open import Relation.Nullary
+open import logic
+
+
+--
+--
+--  no children , having left node , having right node , having both
+--
+data bt {n : Level} (A : Set n) : Set n where
+  leaf : bt A
+  node :  (key : ℕ) → (value : A) →
+    (left : bt A ) → (right : bt A ) → bt A
+
+node-key : {n : Level} {A : Set n} → bt A → Maybe ℕ
+node-key (node key _ _ _) = just key
+node-key _ = nothing
+
+node-value : {n : Level} {A : Set n} → bt A → Maybe A
+node-value (node _ value _ _) = just value
+node-value _ = nothing
+
+bt-depth : {n : Level} {A : Set n} → (tree : bt A ) → ℕ
+bt-depth leaf = 0
+bt-depth (node key value t t₁) = suc (bt-depth t  ⊔ bt-depth t₁ )
+
+bt-ne : {n : Level} {A : Set n} {key : ℕ} {value : A} {t t₁ : bt A} → ¬ ( leaf ≡ node key value t t₁ )
+bt-ne {n} {A} {key} {value} {t} {t₁} ()
+
+open import Data.Unit hiding ( _≟_ ) -- ;  _≤?_ ; _≤_)
+
+tr< : {n : Level} {A : Set n} → (key : ℕ) → bt A → Set
+tr< {_} {A} key leaf = ⊤
+tr< {_} {A} key (node key₁ value tr tr₁) = (key₁ < key ) ∧ tr< key tr  ∧  tr< key tr₁
+
+tr> : {n : Level} {A : Set n} → (key : ℕ) → bt A → Set
+tr> {_} {A} key leaf = ⊤
+tr> {_} {A} key (node key₁ value tr tr₁) = (key < key₁ ) ∧ tr> key tr  ∧  tr> key tr₁
+
+--
+--
+data treeInvariant {n : Level} {A : Set n} : (tree : bt A) → Set n where
+    t-leaf : treeInvariant leaf
+    t-single : (key : ℕ) → (value : A) →  treeInvariant (node key value leaf leaf)
+    t-right : (key key₁ : ℕ) → {value value₁ : A} → {t₁ t₂ : bt A} → key < key₁
+       → tr> key t₁
+       → tr> key t₂
+       → treeInvariant (node key₁ value₁ t₁ t₂)
+       → treeInvariant (node key value leaf (node key₁ value₁ t₁ t₂))
+    t-left  : (key key₁ : ℕ) → {value value₁ : A} → {t₁ t₂ : bt A} → key < key₁
+       → tr< key₁ t₁
+       → tr< key₁ t₂
+       → treeInvariant (node key value t₁ t₂)
+       → treeInvariant (node key₁ value₁ (node key value t₁ t₂) leaf )
+    t-node  : (key key₁ key₂ : ℕ) → {value value₁ value₂ : A} → {t₁ t₂ t₃ t₄ : bt A} → key < key₁ → key₁ < key₂
+       → tr< key₁ t₁
+       → tr< key₁ t₂
+       → tr> key₁ t₃
+       → tr> key₁ t₄
+       → treeInvariant (node key value t₁ t₂)
+       → treeInvariant (node key₂ value₂ t₃ t₄)
+       → treeInvariant (node key₁ value₁ (node key value t₁ t₂) (node key₂ value₂ t₃ t₄))
+
+--
+--  stack always contains original top at end (path of the tree)
+--
+data stackInvariant {n : Level} {A : Set n}  (key : ℕ) : (top orig : bt A) → (stack  : List (bt A)) → Set n where
+    s-nil :  {tree0 : bt A} → stackInvariant key tree0 tree0 (tree0 ∷ [])
+    s-right :  (tree tree0 tree₁ : bt A) → {key₁ : ℕ } → {v1 : A } → {st : List (bt A)}
+        → key₁ < key  →  stackInvariant key (node key₁ v1 tree₁ tree) tree0 st → stackInvariant key tree tree0 (tree ∷ st)
+    s-left :  (tree₁ tree0 tree : bt A) → {key₁ : ℕ } → {v1 : A } → {st : List (bt A)}
+        → key  < key₁ →  stackInvariant key (node key₁ v1 tree₁ tree) tree0 st → stackInvariant key tree₁ tree0 (tree₁ ∷ st)
+
+add< : { i : ℕ } (j : ℕ ) → i < suc i + j
+add<  {i} j = begin
+        suc i ≤⟨ m≤m+n (suc i) j ⟩
+        suc i + j ∎  where open ≤-Reasoning
+
+nat-≤> : { x y : ℕ } → x ≤ y → y < x → ⊥
+nat-≤>  (s≤s x<y) (s≤s y<x) = nat-≤> x<y y<x
+nat-<> : { x y : ℕ } → x < y → y < x → ⊥
+nat-<>  (s≤s x<y) (s≤s y<x) = nat-<> x<y y<x
+
+nat-<≡ : { x : ℕ } → x < x → ⊥
+nat-<≡  (s≤s lt) = nat-<≡ lt
+
+nat-≡< : { x y : ℕ } → x ≡ y → x < y → ⊥
+nat-≡< refl lt = nat-<≡ lt
+
+treeTest1  : bt ℕ
+treeTest1  =  node 0 0 leaf (node 3 1 (node 2 5 (node 1 7 leaf leaf ) leaf) (node 5 5 leaf leaf))
+treeTest2  : bt ℕ
+treeTest2  =  node 3 1 (node 2 5 (node 1 7 leaf leaf ) leaf) (node 5 5 leaf leaf)
+
+treeInvariantTest1  : treeInvariant treeTest1
+treeInvariantTest1  = t-right _ _ (m≤m+n _ 2)
+    ⟪ add< _ , ⟪ ⟪ add< _ , _ ⟫ , _ ⟫ ⟫
+    ⟪ add< _ , ⟪ _ , _ ⟫ ⟫ (t-node _ _ _ (add< 0) (add< 1) ⟪ add< _ , ⟪ _ , _ ⟫ ⟫  _ _ _ (t-left _ _ (add< 0) _ _ (t-single 1 7)) (t-single 5 5) )
+
+stack-top :  {n : Level} {A : Set n} (stack  : List (bt A)) → Maybe (bt A)
+stack-top [] = nothing
+stack-top (x ∷ s) = just x
+
+stack-last :  {n : Level} {A : Set n} (stack  : List (bt A)) → Maybe (bt A)
+stack-last [] = nothing
+stack-last (x ∷ []) = just x
+stack-last (x ∷ s) = stack-last s
+
+stackInvariantTest1 : stackInvariant 4 treeTest2 treeTest1 ( treeTest2 ∷ treeTest1 ∷ [] )
+stackInvariantTest1 = s-right _ _ _ (add< 3) (s-nil  )
+
+si-property0 :  {n : Level} {A : Set n} {key : ℕ} {tree tree0 : bt A} → {stack  : List (bt A)} →  stackInvariant key tree tree0 stack → ¬ ( stack ≡ [] )
+si-property0  (s-nil  ) ()
+si-property0  (s-right _ _ _ x si) ()
+si-property0  (s-left _ _ _ x si) ()
+
+si-property1 :  {n : Level} {A : Set n} {key : ℕ} {tree tree0 tree1 : bt A} → {stack  : List (bt A)} →  stackInvariant key tree tree0 (tree1 ∷ stack)
+   → tree1 ≡ tree
+si-property1 (s-nil   ) = refl
+si-property1 (s-right _ _ _ _  si) = refl
+si-property1 (s-left _ _ _ _  si) = refl
+
+si-property2 :  {n : Level} {A : Set n} {key : ℕ} {tree tree0 tree1 : bt A} → (stack  : List (bt A)) →  stackInvariant key tree tree0 (tree1 ∷ stack)
+   → ¬ ( just leaf ≡ stack-last stack )
+si-property2 (.leaf ∷ []) (s-right _ _ tree₁ x ()) refl
+si-property2 (x₁ ∷ x₂ ∷ stack) (s-right _ _ tree₁ x si) eq = si-property2 (x₂ ∷ stack) si eq
+si-property2 (.leaf ∷ []) (s-left _ _ tree₁ x ()) refl
+si-property2 (x₁ ∷ x₂ ∷ stack) (s-left _ _ tree₁ x si) eq = si-property2 (x₂ ∷ stack) si eq
+
+si-property-< :  {n : Level} {A : Set n} {key kp : ℕ} {value₂ : A} {tree orig tree₃ : bt A} → {stack  : List (bt A)}
+   → ¬ ( tree ≡ leaf )
+   → treeInvariant (node kp value₂ tree  tree₃ )
+   → stackInvariant key tree orig (tree ∷ node kp value₂ tree  tree₃ ∷ stack)
+   → key < kp
+si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x s-nil) = ⊥-elim (nat-<> x₁ x₂)
+si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x (s-right .(node _ _ (node _ _ _ _) (node _ _ _ _)) _ tree₁ x₇ si)) = ⊥-elim (nat-<> x₁ x₂)
+si-property-< ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x (s-left .(node _ _ (node _ _ _ _) (node _ _ _ _)) _ tree x₇ si)) = ⊥-elim (nat-<> x₁ x₂)
+si-property-< ne ti (s-left _ _ _ x (s-right .(node _ _ _ _) _ tree₁ x₁ si)) = x
+si-property-< ne ti (s-left _ _ _ x (s-left .(node _ _ _ _) _ tree₁ x₁ si)) = x
+si-property-< ne ti (s-left _ _ _ x s-nil) = x
+si-property-< ne (t-single _ _) (s-right _ _ tree₁ x si) = ⊥-elim ( ne refl )
+
+si-property-> :  {n : Level} {A : Set n} {key kp : ℕ} {value₂ : A} {tree orig tree₃ : bt A} → {stack  : List (bt A)}
+   → ¬ ( tree ≡ leaf )
+   → treeInvariant (node kp value₂ tree₃  tree )
+   → stackInvariant key tree orig (tree ∷ node kp value₂ tree₃  tree ∷ stack)
+   → kp < key
+si-property-> ne ti (s-right _ _ tree₁ x s-nil) = x
+si-property-> ne ti (s-right _ _ tree₁ x (s-right .(node _ _ tree₁ _) _ tree₂ x₁ si)) = x
+si-property-> ne ti (s-right _ _ tree₁ x (s-left .(node _ _ tree₁ _) _ tree x₁ si)) = x
+si-property-> ne (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-left _ _ _ x s-nil) = ⊥-elim (nat-<> x₁ x₂)
+si-property-> ne (t-node _ _ _ x₂ x₃ x₄ x₅ x₆ x₇ ti ti₁) (s-left _ _ _ x (s-right .(node _ _ _ _) _ tree₁ x₁ si)) = ⊥-elim (nat-<> x₂ x₃)
+si-property-> ne (t-node _ _ _ x₂ x₃ x₄ x₅ x₆ x₇ ti ti₁) (s-left _ _ _ x (s-left .(node _ _ _ _) _ tree x₁ si)) = ⊥-elim (nat-<> x₂ x₃)
+si-property-> ne (t-single _ _) (s-left _ _ _ x s-nil) = ⊥-elim ( ne refl )
+si-property-> ne (t-single _ _) (s-left _ _ _ x (s-right .(node _ _ leaf leaf) _ tree₁ x₁ si)) = ⊥-elim ( ne refl )
+si-property-> ne (t-single _ _) (s-left _ _ _ x (s-left .(node _ _ leaf leaf) _ tree x₁ si)) = ⊥-elim ( ne refl )
+
+si-property-last :  {n : Level} {A : Set n}  (key : ℕ) (tree tree0 : bt A) → (stack  : List (bt A)) →  stackInvariant key tree tree0 stack
+   → stack-last stack ≡ just tree0
+si-property-last key t t0 (t ∷ [])  (s-nil )  = refl
+si-property-last key t t0 (.t ∷ x ∷ st) (s-right _ _ _ _ si ) with  si-property1 si
+... | refl = si-property-last key x t0 (x ∷ st)   si
+si-property-last key t t0 (.t ∷ x ∷ st) (s-left _ _ _ _ si ) with  si-property1  si
+... | refl = si-property-last key x t0 (x ∷ st)   si
+
+si-property-pne :  {n : Level} {A : Set n}  {key key₁ : ℕ} {value₁ : A} (tree orig : bt A) → {left right x : bt A} → (stack  : List (bt A)) {rest : List (bt A)}
+    → stack ≡ x ∷ node key₁ value₁ left right ∷ rest
+    → stackInvariant key tree orig stack
+    → ¬ ( key ≡ key₁ )
+si-property-pne tree orig .(tree ∷ node _ _ _ _ ∷ _) refl (s-right .tree .orig tree₁ x si) eq with si-property1 si
+... | refl = ⊥-elim ( nat-≡< (sym eq) x)
+si-property-pne tree orig .(tree ∷ node _ _ _ _ ∷ _) refl (s-left .tree .orig tree₁ x si) eq with si-property1 si
+... | refl = ⊥-elim ( nat-≡< eq x)
+
+si-property-parent-node :  {n : Level} {A : Set n}  {key : ℕ}  (tree orig : bt A) {x : bt A}
+    → (stack  : List (bt A)) {rest : List (bt A)}
+    → stackInvariant key tree orig stack
+    → ¬ ( stack ≡ x ∷ leaf ∷ rest )
+si-property-parent-node {n} {A} tree orig .(tree ∷ leaf ∷ _) (s-right .tree .orig tree₁ x si) refl with si-property1 si
+... | ()
+si-property-parent-node {n} {A} tree orig .(tree ∷ leaf ∷ _) (s-left .tree .orig tree₁ x si) refl with si-property1 si
+... | ()
+
+
+
+open _∧_
+
+
+depth-1< : {i j : ℕ} →   suc i ≤ suc (i Data.Nat.⊔ j )
+depth-1< {i} {j} = s≤s (m≤m⊔n _ j)
+
+depth-2< : {i j : ℕ} →   suc i ≤ suc (j Data.Nat.⊔ i )
+depth-2< {i} {j} = s≤s (m≤n⊔m j i)
+
+depth-3< : {i : ℕ } → suc i ≤ suc (suc i)
+depth-3< {zero} = s≤s ( z≤n )
+depth-3< {suc i} = s≤s (depth-3< {i} )
+
+
+treeLeftDown  : {n : Level} {A : Set n} {k : ℕ} {v1 : A}  → (tree tree₁ : bt A )
+      → treeInvariant (node k v1 tree tree₁)
+      →      treeInvariant tree
+treeLeftDown {n} {A} {_} {v1} leaf leaf (t-single k1 v1) = t-leaf
+treeLeftDown {n} {A} {_} {v1} .leaf .(node _ _ _ _) (t-right _ _ x _ _ ti) = t-leaf
+treeLeftDown {n} {A} {_} {v1} .(node _ _ _ _) .leaf (t-left _ _ x _ _ ti) = ti
+treeLeftDown {n} {A} {_} {v1} .(node _ _ _ _) .(node _ _ _ _) (t-node _ _ _ x x₁ _ _ _ _ ti ti₁) = ti
+
+treeRightDown  : {n : Level} {A : Set n} {k : ℕ} {v1 : A}  → (tree tree₁ : bt A )
+      → treeInvariant (node k v1 tree tree₁)
+      →      treeInvariant tree₁
+treeRightDown {n} {A} {_} {v1} .leaf .leaf (t-single _ .v1) = t-leaf
+treeRightDown {n} {A} {_} {v1} .leaf .(node _ _ _ _) (t-right _ _ x _ _ ti) = ti
+treeRightDown {n} {A} {_} {v1} .(node _ _ _ _) .leaf (t-left _ _ x _ _ ti) = t-leaf
+treeRightDown {n} {A} {_} {v1} .(node _ _ _ _) .(node _ _ _ _) (t-node _ _ _ x x₁ _ _ _ _ ti ti₁) = ti₁
+
+ti-property1 :  {n : Level} {A : Set n} {key₁ : ℕ} {value₂ : A} {left right : bt A} → treeInvariant (node key₁ value₂  left right ) →   tr< key₁ left ∧  tr> key₁ right
+ti-property1 {n} {A} {key₁} {value₂} {.leaf} {.leaf} (t-single .key₁ .value₂) = ⟪ tt , tt ⟫
+ti-property1 {n} {A} {key₁} {value₂} {.leaf} {.(node key₂ _ _ _)} (t-right .key₁ key₂ x x₁ x₂ t) = ⟪ tt , ⟪ x , ⟪ x₁ , x₂ ⟫ ⟫ ⟫
+ti-property1 {n} {A} {key₁} {value₂} {.(node key _ _ _)} {.leaf} (t-left key .key₁ x x₁ x₂ t) = ⟪ ⟪ x , ⟪ x₁ , x₂ ⟫ ⟫ , tt ⟫
+ti-property1 {n} {A} {key₁} {value₂} {.(node key _ _ _)} {.(node key₂ _ _ _)} (t-node key .key₁ key₂ x x₁ x₂ x₃ x₄ x₅ t t₁)
+     = ⟪ ⟪ x , ⟪ x₂ , x₃ ⟫ ⟫ , ⟪ x₁ , ⟪ x₄ , x₅ ⟫ ⟫ ⟫
+
+
+findP : {n m : Level} {A : Set n} {t : Set m} → (key : ℕ) → (tree tree0 : bt A ) → (stack : List (bt A))
+           →  treeInvariant tree ∧ stackInvariant key tree tree0 stack
+           → (next : (tree1 : bt A) → (stack : List (bt A)) → treeInvariant tree1 ∧ stackInvariant key tree1 tree0 stack → bt-depth tree1 < bt-depth tree   → t )
+           → (exit : (tree1 : bt A) → (stack : List (bt A)) → treeInvariant tree1 ∧ stackInvariant key tree1 tree0 stack
+                 → (tree1 ≡ leaf ) ∨ ( node-key tree1 ≡ just key )  → t ) → t
+findP key leaf tree0 st Pre _ exit = exit leaf st Pre (case1 refl)
+findP key (node key₁ v1 tree tree₁) tree0 st Pre next exit with <-cmp key key₁
+findP key n tree0 st Pre _ exit | tri≈ ¬a refl ¬c = exit n st Pre (case2 refl)
+findP {n} {_} {A} key (node key₁ v1 tree tree₁) tree0 st  Pre next _ | tri< a ¬b ¬c = next tree (tree ∷ st)
+       ⟪ treeLeftDown tree tree₁ (proj1 Pre)  , findP1 a st (proj2 Pre) ⟫ depth-1< where
+   findP1 : key < key₁ → (st : List (bt A)) →  stackInvariant key (node key₁ v1 tree tree₁) tree0 st → stackInvariant key tree tree0 (tree ∷ st)
+   findP1 a (x ∷ st) si = s-left _ _ _ a si
+findP key n@(node key₁ v1 tree tree₁) tree0 st Pre next _ | tri> ¬a ¬b c = next tree₁ (tree₁ ∷ st) ⟪ treeRightDown tree tree₁ (proj1 Pre) , s-right _ _ _ c (proj2 Pre) ⟫ depth-2<
+
+replaceTree1 : {n  : Level} {A : Set n} {t t₁ : bt A } → ( k : ℕ ) → (v1 value : A ) →  treeInvariant (node k v1 t t₁) → treeInvariant (node k value t t₁)
+replaceTree1 k v1 value (t-single .k .v1) = t-single k value
+replaceTree1 k v1 value (t-right _ _ x a b t) = t-right _ _ x a b t
+replaceTree1 k v1 value (t-left _ _ x a b t) = t-left _ _ x a b t
+replaceTree1 k v1 value (t-node _ _ _ x x₁ a b c d t t₁) = t-node _ _ _ x x₁ a b c d t t₁
+
+open import Relation.Binary.Definitions
+
+lemma3 : {i j : ℕ} → 0 ≡ i → j < i → ⊥
+lemma3 refl ()
+lemma5 : {i j : ℕ} → i < 1 → j < i → ⊥
+lemma5 (s≤s z≤n) ()
+¬x<x : {x : ℕ} → ¬ (x < x)
+¬x<x (s≤s lt) = ¬x<x lt
+
+child-replaced :  {n : Level} {A : Set n} (key : ℕ)   (tree : bt A) → bt A
+child-replaced key leaf = leaf
+child-replaced key (node key₁ value left right) with <-cmp key key₁
+... | tri< a ¬b ¬c = left
+... | tri≈ ¬a b ¬c = node key₁ value left right
+... | tri> ¬a ¬b c = right
+
+child-replaced-left :  {n : Level} {A : Set n} {key key₁ : ℕ}  {value : A}  {left right : bt A}
+   → key < key₁
+   → child-replaced key (node key₁ value left right) ≡ left
+child-replaced-left {n} {A} {key} {key₁} {value} {left} {right} lt = ch00 (node key₁ value left right) refl lt where
+     ch00 : (tree : bt A) → tree ≡ node key₁ value left right → key < key₁ → child-replaced key tree ≡ left
+     ch00 (node key₁ value tree tree₁) refl lt1 with <-cmp key key₁
+     ... | tri< a ¬b ¬c = refl
+     ... | tri≈ ¬a b ¬c = ⊥-elim (¬a lt1)
+     ... | tri> ¬a ¬b c = ⊥-elim (¬a lt1)
+
+child-replaced-right :  {n : Level} {A : Set n} {key key₁ : ℕ}  {value : A}  {left right : bt A}
+   → key₁ < key
+   → child-replaced key (node key₁ value left right) ≡ right
+child-replaced-right {n} {A} {key} {key₁} {value} {left} {right} lt = ch00 (node key₁ value left right) refl lt where
+     ch00 : (tree : bt A) → tree ≡ node key₁ value left right → key₁ < key → child-replaced key tree ≡ right
+     ch00 (node key₁ value tree tree₁) refl lt1 with <-cmp key key₁
+     ... | tri< a ¬b ¬c = ⊥-elim (¬c lt1)
+     ... | tri≈ ¬a b ¬c = ⊥-elim (¬c lt1)
+     ... | tri> ¬a ¬b c = refl
+
+child-replaced-eq :  {n : Level} {A : Set n} {key key₁ : ℕ}  {value : A}  {left right : bt A}
+   → key₁ ≡ key
+   → child-replaced key (node key₁ value left right) ≡ node key₁ value left right
+child-replaced-eq {n} {A} {key} {key₁} {value} {left} {right} lt = ch00 (node key₁ value left right) refl lt where
+     ch00 : (tree : bt A) → tree ≡ node key₁ value left right → key₁ ≡ key → child-replaced key tree ≡ node key₁ value left right
+     ch00 (node key₁ value tree tree₁) refl lt1 with <-cmp key key₁
+     ... | tri< a ¬b ¬c = ⊥-elim (¬b (sym lt1))
+     ... | tri≈ ¬a b ¬c = refl
+     ... | tri> ¬a ¬b c = ⊥-elim (¬b (sym lt1))
+
+record replacePR {n : Level} {A : Set n} (key : ℕ) (value : A) (tree repl : bt A ) (stack : List (bt A)) (C : bt A → bt A → List (bt A) → Set n) : Set n where
+   field
+     tree0 : bt A
+     ti : treeInvariant tree0
+     si : stackInvariant key tree tree0 stack
+     ci : C tree repl stack     -- data continuation
+
+record replacePR' {n : Level} {A : Set n} (key : ℕ) (value : A) (orig : bt A ) (stack : List (bt A))  : Set n where
+   field
+     tree repl : bt A
+     ti : treeInvariant orig
+     si : stackInvariant key tree orig stack
+     --   treeInvariant of tree and repl is inferred from ti, si and ri.
+
+replaceNodeP : {n m : Level} {A : Set n} {t : Set m} → (key : ℕ) → (value : A) → (tree : bt A)
+    → (tree ≡ leaf ) ∨ ( node-key tree ≡ just key )
+    → (treeInvariant tree ) → ((tree1 : bt A) → treeInvariant tree1 → t) → t
+replaceNodeP k v1 leaf C P next = next (node k v1 leaf leaf) (t-single k v1 ) 
+replaceNodeP k v1 (node .k value t t₁) (case2 refl) P next = next (node k v1 t t₁) (replaceTree1 k value v1 P) where
+         repl00 : node k value t t₁ ≡ child-replaced k (node k value t t₁)
+         repl00 with <-cmp k k
+         ... | tri< a ¬b ¬c = ⊥-elim (¬b refl)
+         ... | tri≈ ¬a b ¬c = refl
+         ... | tri> ¬a ¬b c = ⊥-elim (¬b refl)
+
+replaceP : {n m : Level} {A : Set n} {t : Set m}
+     → (key : ℕ) → (value : A) → {tree : bt A} ( repl : bt A)
+     → (stack : List (bt A)) → replacePR key value tree repl stack (λ _ _ _ → Lift n ⊤)
+     → (next : ℕ → A → {tree1 : bt A } (repl : bt A) → (stack1 : List (bt A))
+         → replacePR key value tree1 repl stack1 (λ _ _ _ → Lift n ⊤) → length stack1 < length stack → t)
+     → (exit : (tree1 repl : bt A) → t) → t
+replaceP key value {tree}  repl [] Pre next exit = ⊥-elim ( si-property0 (replacePR.si Pre) refl ) -- can't happen
+replaceP key value {tree}  repl (leaf ∷ []) Pre next exit with  si-property-last  _ _ _ _  (replacePR.si Pre)-- tree0 ≡ leaf
+... | refl  =  exit (replacePR.tree0 Pre) (node key value leaf leaf) 
+replaceP key value {tree}  repl (node key₁ value₁ left right ∷ []) Pre next exit with <-cmp key key₁
+... | tri< a ¬b ¬c = exit (replacePR.tree0 Pre) (node key₁ value₁ repl right ) 
+... | tri≈ ¬a b ¬c = exit (replacePR.tree0 Pre) repl 
+... | tri> ¬a ¬b c = exit (replacePR.tree0 Pre) (node key₁ value₁ left repl  ) 
+replaceP {n} {_} {A} key value  {tree}  repl (leaf ∷ st@(tree1 ∷ st1)) Pre next exit = next key value repl st Post ≤-refl where
+    Post :  replacePR key value tree1 repl (tree1 ∷ st1) (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ leaf
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 tree₁ leaf) ≡ leaf
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = ⊥-elim (¬c x)
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬c x)
+        ... |  tri> ¬a ¬b c = refl
+    ... | s-left  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 leaf tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 leaf tree₁ ) ≡ leaf
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = refl
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬a x)
+        ... |  tri> ¬a ¬b c = ⊥-elim (¬a x)
+replaceP {n} {_} {A} key value {tree}  repl (node key₁ value₁ left right ∷ st@(tree1 ∷ st1)) Pre next exit  with <-cmp key key₁
+... | tri< a ¬b ¬c = next key value (node key₁ value₁ repl right ) st Post ≤-refl where
+    Post : replacePR key value tree1 (node key₁ value₁ repl right ) st (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ (node key₁ value₁ left right)
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ left
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = refl
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
+        ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
+        repl02 : child-replaced key (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri> ¬a ¬b c = refl
+        repl04 : node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡⟨ cong (λ k → node key₁ value₁ k right) repl03  ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+    ... | s-left _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 (node key₁ value₁ left right) tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ left
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = refl
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
+        ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
+        repl02 : child-replaced key (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = refl
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬a lt)
+        ... | refl | tri> ¬a ¬b c = ⊥-elim (¬a lt)
+        repl04 : node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ (child-replaced key (node key₁ value₁ left right)) right ≡⟨ cong (λ k → node key₁ value₁ k right) repl03  ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+... | tri≈ ¬a b ¬c = next key value (node key₁ value  left right ) st Post ≤-refl where
+    Post :  replacePR key value tree1 (node key₁ value left right ) (tree1 ∷ st1) (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ;  ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ tree -- (node key₁ value₁  left right)
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 tree₁ tree) ≡ tree
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = ⊥-elim (¬c x)
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬c x)
+        ... |  tri> ¬a ¬b c = refl
+    ... | s-left  _ _ tree₁ {key₂} {v1} x si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ;  ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl07 : child-replaced key (node key₂ v1 tree tree₁ ) ≡ tree
+        repl07 with <-cmp key key₂
+        ... |  tri< a ¬b ¬c = refl
+        ... |  tri≈ ¬a b ¬c = ⊥-elim (¬a x)
+        ... |  tri> ¬a ¬b c = ⊥-elim (¬a x)
+... | tri> ¬a ¬b c = next key value (node key₁ value₁ left repl ) st Post ≤-refl where
+    Post : replacePR key value tree1 (node key₁ value₁ left repl ) st (λ _ _ _ → Lift n ⊤)
+    Post with replacePR.si Pre
+    ... | s-right _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ;  ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 tree₁ (node key₁ value₁ left right)
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ right
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = ⊥-elim (¬c c)
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
+        ... | tri> ¬a ¬b c = refl
+        repl02 : child-replaced key (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬c lt)
+        ... | refl | tri> ¬a ¬b c = refl
+        repl04 : node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡⟨ cong (λ k → node key₁ value₁ left k ) repl03 ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 tree₁ (node key₁ value₁ left right) ) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+    ... | s-left _ _ tree₁ {key₂} {v1} lt si = record { tree0 = replacePR.tree0 Pre ; ti = replacePR.ti Pre ; si = repl10 ; ci = lift tt } where
+        repl09 : tree1 ≡ node key₂ v1 (node key₁ value₁ left right) tree₁
+        repl09 = si-property1 si
+        repl10 : stackInvariant key tree1 (replacePR.tree0 Pre) (tree1 ∷ st1)
+        repl10 with si-property1 si
+        ... | refl = si
+        repl03 : child-replaced key (node key₁ value₁ left right) ≡ right
+        repl03 with <-cmp key key₁
+        ... | tri< a1 ¬b ¬c = ⊥-elim (¬c c)
+        ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
+        ... | tri> ¬a ¬b c = refl
+        repl02 : child-replaced key (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡ node key₁ value₁ left right
+        repl02 with repl09 | <-cmp key key₂
+        ... | refl | tri< a ¬b ¬c = refl
+        ... | refl | tri≈ ¬a b ¬c = ⊥-elim (¬a lt)
+        ... | refl | tri> ¬a ¬b c = ⊥-elim (¬a lt)
+        repl04 : node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡ child-replaced key tree1
+        repl04  = begin
+            node key₁ value₁ left (child-replaced key (node key₁ value₁ left right)) ≡⟨ cong (λ k → node key₁ value₁ left k ) repl03 ⟩
+            node key₁ value₁ left right ≡⟨ sym repl02 ⟩
+            child-replaced key  (node key₂ v1 (node key₁ value₁ left right) tree₁) ≡⟨ cong (λ k → child-replaced key k ) (sym repl09) ⟩
+            child-replaced key tree1 ∎  where open ≡-Reasoning
+
+TerminatingLoopS : {l m : Level} {t : Set l} (Index : Set m ) → {Invraiant : Index → Set m } → ( reduce : Index → ℕ)
+   → (r : Index) → (p : Invraiant r)
+   → (loop : (r : Index)  → Invraiant r → (next : (r1 : Index)  → Invraiant r1 → reduce r1 < reduce r  → t ) → t) → t
+TerminatingLoopS {_} {_} {t} Index {Invraiant} reduce r p loop with <-cmp 0 (reduce r)
+... | tri≈ ¬a b ¬c = loop r p (λ r1 p1 lt → ⊥-elim (lemma3 b lt) )
+... | tri< a ¬b ¬c = loop r p (λ r1 p1 lt1 → TerminatingLoop1 (reduce r) r r1 (m≤n⇒m≤1+n lt1) p1 lt1 ) where
+    TerminatingLoop1 : (j : ℕ) → (r r1 : Index) → reduce r1 < suc j  → Invraiant r1 →  reduce r1 < reduce r → t
+    TerminatingLoop1 zero r r1 n≤j p1 lt = loop r1 p1 (λ r2 p1 lt1 → ⊥-elim (lemma5 n≤j lt1))
+    TerminatingLoop1 (suc j) r r1  n≤j p1 lt with <-cmp (reduce r1) (suc j)
+    ... | tri< a ¬b ¬c = TerminatingLoop1 j r r1 a p1 lt
+    ... | tri≈ ¬a b ¬c = loop r1 p1 (λ r2 p2 lt1 → TerminatingLoop1 j r1 r2 (subst (λ k → reduce r2 < k ) b lt1 ) p2 lt1 )
+    ... | tri> ¬a ¬b c =  ⊥-elim ( nat-≤> c n≤j )
+
+open _∧_
+
+
+insertTreeP : {n m : Level} {A : Set n} {t : Set m} → (tree : bt A) → (key : ℕ) → (value : A) → treeInvariant tree
+     → (exit : (tree repl : bt A) → treeInvariant repl → t ) → t
+insertTreeP {n} {m} {A} {t} tree key value ti exit = ?
+--   TerminatingLoopS (bt A ∧ List (bt A) ) {λ p → treeInvariant (proj1 p) ∧ stackInvariant key (proj1 p) tree (proj2 p) } (λ p → bt-depth (proj1 p)) ⟪ tree , tree ∷ [] ⟫  ⟪ ? , s-nil ⟫
+--       $ λ p P loop → findP key (proj1 p)  tree (proj2 p) P (λ t s P1 lt → loop ⟪ t ,  s  ⟫ P1 lt )
+--       $ λ t s P C → replaceNodeP key value t C (proj1 P)
+--       $ λ t1 P1 R → TerminatingLoopS (List (bt A) ∧ bt A ∧ bt A )
+--            {λ p → replacePR key value  (proj1 (proj2 p)) (proj2 (proj2 p)) (proj1 p)  (λ _ _ _ → Lift n ⊤ ) }
+--               (λ p → length (proj1 p)) ⟪ s , ⟪ t , t1 ⟫ ⟫ record { tree0 = tree ; ti = ? ; si = proj2 P ; ri = R ; ci = lift tt }
+--       $  λ p P1 loop → replaceP key value  (proj2 (proj2 p)) (proj1 p) P1
+--            (λ key value {tree1} repl1 stack P2 lt → loop ⟪ stack , ⟪ tree1 , repl1  ⟫ ⟫ P2 lt )
+--       $ λ tree repl P → exit tree repl ?
+-- 
+insertTestP1 = insertTreeP leaf 1 1 t-leaf
+  $ λ _ x0 P0 → insertTreeP x0 2 1 ?
+  $ λ _ x1 P1 → insertTreeP x1 3 2 ?
+  $ λ _ x2 P2 → insertTreeP x2 2 2 ? (λ _ x P  → x )
+
+top-value : {n : Level} {A : Set n} → (tree : bt A) →  Maybe A
+top-value leaf = nothing
+top-value (node key value tree tree₁) = just value
+
+-- is realy inserted?
+
+-- other element is preserved?
+
+-- deletion?
+
+
+data Color  : Set where
+    Red : Color
+    Black : Color
+
+RB→bt : {n : Level} (A : Set n) → (bt (Color ∧ A)) → bt A
+RB→bt {n} A leaf = leaf
+RB→bt {n} A (node key ⟪ C , value ⟫ tr t1) = (node key value (RB→bt A tr) (RB→bt A t1))
+
+color : {n : Level} {A : Set n} → (bt (Color ∧ A)) → Color
+color leaf = Black
+color (node key ⟪ C , value ⟫ rb rb₁) = C
+
+to-red : {n : Level} {A : Set n} → (tree : bt (Color ∧ A)) → bt (Color ∧ A)
+to-red leaf = leaf
+to-red (node key ⟪ _ , value ⟫ t t₁) = (node key ⟪ Red , value ⟫ t t₁)
+
+to-black : {n : Level} {A : Set n} → (tree : bt (Color ∧ A)) → bt (Color ∧ A)
+to-black leaf = leaf
+to-black (node key ⟪ _ , value ⟫ t t₁) = (node key ⟪ Black , value ⟫ t t₁)
+
+black-depth : {n : Level} {A : Set n} → (tree : bt (Color ∧ A) ) → ℕ
+black-depth leaf = 1
+black-depth (node key ⟪ Red , value ⟫  t t₁) = black-depth t  ⊔ black-depth t₁
+black-depth (node key ⟪ Black , value ⟫  t t₁) = suc (black-depth t  ⊔ black-depth t₁ )
+
+zero≢suc : { m : ℕ } → zero ≡ suc m → ⊥
+zero≢suc ()
+suc≢zero : {m : ℕ } → suc m ≡ zero → ⊥
+suc≢zero ()
+
+data RBtreeInvariant {n : Level} {A : Set n} : (tree : bt (Color ∧ A)) → Set n where
+    rb-leaf :  RBtreeInvariant leaf
+    rb-red :  (key : ℕ) → (value : A) → {left right : bt (Color ∧ A)}
+       → color left ≡ Black → color right ≡ Black
+       → black-depth left ≡ black-depth right
+       → RBtreeInvariant left → RBtreeInvariant right
+       → RBtreeInvariant (node key ⟪ Red , value ⟫ left right)
+    rb-black :  (key : ℕ) → (value : A) → {left right : bt (Color ∧ A)}
+       → black-depth left ≡ black-depth right
+       → RBtreeInvariant left → RBtreeInvariant right
+       → RBtreeInvariant (node key ⟪ Black , value ⟫ left right)
+
+RightDown : {n : Level} {A : Set n} → bt (Color ∧ A) → bt (Color ∧ A)
+RightDown leaf = leaf
+RightDown (node key ⟪ c , value ⟫ t1 t2) = t2
+LeftDown : {n : Level} {A :  Set n} → bt (Color ∧ A) → bt (Color ∧ A)
+LeftDown leaf = leaf
+LeftDown (node key ⟪ c , value ⟫ t1 t2 ) = t1
+
+RBtreeLeftDown : {n : Level} {A : Set n} {key : ℕ} {value : A} {c : Color}
+ →  (left right : bt (Color ∧ A))
+ → RBtreeInvariant (node key ⟪ c , value ⟫ left right)
+ → RBtreeInvariant left
+RBtreeLeftDown left right (rb-red _ _ x x₁ x₂ rb rb₁) = rb
+RBtreeLeftDown left right (rb-black _ _ x rb rb₁) = rb
+
+
+RBtreeRightDown : {n : Level} {A : Set n} { key : ℕ} {value : A} {c : Color}
+ → (left right : bt (Color ∧ A))
+ → RBtreeInvariant (node key ⟪ c , value ⟫ left right)
+ → RBtreeInvariant right
+RBtreeRightDown left right (rb-red _ _ x x₁ x₂ rb rb₁) = rb₁
+RBtreeRightDown left right (rb-black _ _ x rb rb₁) = rb₁
+
+RBtreeEQ : {n : Level} {A : Set n} {key : ℕ} {value : A} {c : Color}
+ → {left right : bt (Color ∧ A)}
+ → RBtreeInvariant (node key ⟪ c , value ⟫ left right)
+ → black-depth left ≡ black-depth right
+RBtreeEQ  (rb-red _ _ x x₁ x₂ rb rb₁) = x₂
+RBtreeEQ  (rb-black _ _ x rb rb₁) = x
+
+RBtreeToBlack : {n : Level} {A : Set n}
+ → (tree : bt (Color ∧ A))
+ → RBtreeInvariant tree
+ → RBtreeInvariant (to-black tree)
+RBtreeToBlack leaf rb-leaf = rb-leaf
+RBtreeToBlack (node key ⟪ Red , value ⟫ left right) (rb-red _ _ x x₁ x₂ rb rb₁) = rb-black key value x₂ rb rb₁
+RBtreeToBlack (node key ⟪ Black , value ⟫ left right) (rb-black _ _ x rb rb₁) = rb-black key value x rb rb₁
+
+RBtreeToBlackColor : {n : Level} {A : Set n}
+ → (tree : bt (Color ∧ A))
+ → RBtreeInvariant tree
+ → color (to-black tree) ≡ Black
+RBtreeToBlackColor leaf rb-leaf = refl
+RBtreeToBlackColor (node key ⟪ Red , value ⟫ left right) (rb-red _ _ x x₁ x₂ rb rb₁) = refl
+RBtreeToBlackColor (node key ⟪ Black , value ⟫ left right) (rb-black _ _ x rb rb₁) = refl
+
+RBtreeParentColorBlack : {n : Level} {A : Set n} → (left right  : bt (Color ∧ A)) { value : A} {key : ℕ} { c : Color}
+ → RBtreeInvariant (node key ⟪ c , value ⟫ left right)
+ → (color left ≡ Red) ∨ (color right ≡ Red)
+ → c ≡ Black
+RBtreeParentColorBlack leaf leaf (rb-red _ _ x₁ x₂ x₃ x₄ x₅) (case1 ())
+RBtreeParentColorBlack leaf leaf (rb-red _ _ x₁ x₂ x₃ x₄ x₅) (case2 ())
+RBtreeParentColorBlack (node key ⟪ Red , proj4 ⟫ left left₁) right (rb-red _ _ () x₁ x₂ rb rb₁) (case1 x₃)
+RBtreeParentColorBlack (node key ⟪ Black , proj4 ⟫ left left₁) right (rb-red _ _ x x₁ x₂ rb rb₁) (case1 ())
+RBtreeParentColorBlack left (node key ⟪ Red , proj4 ⟫ right right₁) (rb-red _ _ x () x₂ rb rb₁) (case2 x₃)
+RBtreeParentColorBlack left (node key ⟪ Black , proj4 ⟫ right right₁) (rb-red _ _ x x₁ x₂ rb rb₁) (case2 ())
+RBtreeParentColorBlack left right (rb-black _ _ x rb rb₁) x₃ = refl
+
+RBtreeChildrenColorBlack : {n : Level} {A : Set n} → (left right  : bt (Color ∧ A)) { value : Color ∧ A} {key : ℕ}
+ → RBtreeInvariant (node key value left right)
+ → proj1 value  ≡ Red
+ → (color left ≡ Black) ∧  (color right ≡ Black)
+RBtreeChildrenColorBlack left right (rb-red _ _ x x₁ x₂ rbi rbi₁) refl = ⟪ x , x₁ ⟫
+
+--
+--  findRBT exit with replaced node
+--     case-eq        node value is replaced,  just do replacedTree and rebuild rb-invariant
+--     case-leaf      insert new single node
+--        case1       if parent node is black, just do replacedTree and rebuild rb-invariant
+--        case2       if parent node is red,   increase blackdepth, do rotatation
+--
+
+findRBT : {n m : Level} {A : Set n} {t : Set m} → (key : ℕ) → (tree tree0 : bt (Color ∧ A) )
+           → (stack : List (bt (Color ∧ A)))
+           → RBtreeInvariant tree ∧  stackInvariant key tree tree0 stack
+           → (next : (tree1 : bt (Color ∧ A) ) → (stack : List (bt (Color ∧ A)))
+                   → RBtreeInvariant tree1 ∧ stackInvariant key tree1 tree0 stack
+                   → bt-depth tree1 < bt-depth tree → t )
+           → (exit : (tree1 : bt (Color ∧ A)) → (stack : List (bt (Color ∧ A)))
+                 → RBtreeInvariant tree1 ∧ stackInvariant key tree1 tree0 stack
+                 → (tree1 ≡ leaf ) ∨ ( node-key tree1 ≡ just key )  → t ) → t
+findRBT key leaf tree0 stack rb0 next exit = exit leaf stack rb0 (case1 refl)
+findRBT key (node key₁ value left right) tree0 stack rb0 next exit with <-cmp key key₁
+findRBT key (node key₁ value left right) tree0 stack  rb0 next exit | tri< a ¬b ¬c
+ = next left (left ∷ stack) ⟪ RBtreeLeftDown left right (_∧_.proj1 rb0) , s-left _ _ _ a (_∧_.proj2 rb0) ⟫  depth-1<
+findRBT key n tree0 stack  rb0 _ exit | tri≈ ¬a refl ¬c = exit n stack rb0 (case2 refl)
+findRBT key (node key₁ value left right) tree0 stack  rb0 next exit | tri> ¬a ¬b c
+ = next right (right ∷ stack) ⟪ RBtreeRightDown left right (_∧_.proj1 rb0), s-right _ _ _ c (_∧_.proj2 rb0) ⟫ depth-2<
+
+
+
+findTest : {n m : Level} {A : Set n } {t : Set m }
+ → (key : ℕ)
+ → (tree0 : bt (Color ∧ A))
+ → RBtreeInvariant tree0
+ → (exit : (tree1 : bt (Color ∧ A))
+   → (stack : List (bt (Color ∧ A)))
+   → RBtreeInvariant tree1 ∧ stackInvariant key tree1 tree0 stack
+   → (tree1 ≡ leaf ) ∨ ( node-key tree1 ≡ just key )  → t ) → t
+findTest {n} {m} {A} {t} k tr0 rb0 exit = TerminatingLoopS (bt (Color ∧ A) ∧ List (bt (Color ∧ A)))
+ {λ p → RBtreeInvariant (proj1 p) ∧ stackInvariant k (proj1 p) tr0 (proj2 p) } (λ p → bt-depth (proj1 p)) ⟪ tr0 , tr0 ∷ [] ⟫ ⟪ rb0 , s-nil ⟫
+       $ λ p RBP loop → findRBT k (proj1 p) tr0 (proj2 p) RBP  (λ t1 s1 P2 lt1 → loop ⟪ t1 ,  s1  ⟫ P2 lt1 )
+       $ λ tr1 st P2 O → exit tr1 st P2 O
+
+
+testRBTree0 :  bt (Color ∧ ℕ)
+testRBTree0 = node 8 ⟪ Black , 800 ⟫ (node 5 ⟪ Red , 500 ⟫ (node 2 ⟪ Black , 200 ⟫ leaf leaf) (node 6 ⟪ Black , 600 ⟫ leaf leaf)) (node 10 ⟪ Red , 1000 ⟫ (leaf) (node 15 ⟪ Black , 1500 ⟫ (node 14 ⟪ Red , 1400 ⟫ leaf leaf) leaf))
+
+-- testRBI0 : RBtreeInvariant testRBTree0
+-- testRBI0 = rb-node-black (add< 2) (add< 1) refl (rb-node-red (add< 2) (add< 0) refl (rb-single 2 200) (rb-single 6 600)) (rb-right-red (add< 4) refl (rb-left-black (add< 0) refl (rb-single 14 1400) ))
+
+-- findRBTreeTest : result
+-- findRBTreeTest = findTest 14 testRBTree0 testRBI0
+--        $ λ tr s P O → (record {tree = tr ; stack = s ; ti = (proj1 P) ; si = (proj2 P)})
+
+-- create replaceRBTree with rotate
+
+
+--
+-- Parent Grand Relation
+--   should we require stack-invariant?
+--
+
+data ParentGrand {n : Level} {A : Set n} (key : ℕ) (self : bt A) : (parent uncle grand : bt A) → Set n where
+    s2-s1p2 : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
+        → key < kp → parent ≡ node kp vp self n1 → grand ≡ node kg vg parent n2 → ParentGrand key self parent n2 grand
+    s2-1sp2 : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
+        → kp < key → parent ≡ node kp vp n1 self → grand ≡ node kg vg parent n2 → ParentGrand key self parent n2 grand
+    s2-s12p : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
+        → key < kp → parent ≡ node kp vp self n1 → grand ≡ node kg vg n2 parent → ParentGrand key self parent n2 grand
+    s2-1s2p : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
+        → kp < key → parent ≡ node kp vp n1 self → grand ≡ node kg vg n2 parent → ParentGrand key self parent n2 grand
+
+record PG {n : Level } (A : Set n) (key : ℕ) (self : bt A) (stack : List (bt A)) : Set n where
+    field
+       parent grand uncle : bt A
+       pg : ParentGrand key self parent uncle grand
+       rest : List (bt A)
+       stack=gp : stack ≡ ( self ∷ parent ∷ grand ∷ rest )
+
+--
+-- RBI : Invariant on InsertCase2
+--     color repl ≡ Red ∧ black-depth repl ≡ suc (black-depth tree)
+--
+
+data RBI-state  {n : Level} {A : Set n} (key : ℕ) (value : A) : (tree repl : bt (Color ∧ A) ) → (stak : List (bt (Color ∧ A))) → Set n where
+   rebuild : {tree repl : bt (Color ∧ A) } {stack : List (bt (Color ∧ A))} → color tree ≡ color repl → black-depth repl ≡ black-depth tree
+       → ¬ ( tree ≡ leaf)
+       → RBI-state key value tree repl stack  -- one stage up
+   rotate  : (tree : bt (Color ∧ A)) → {repl : bt (Color ∧ A) } {stack : List (bt (Color ∧ A))} → color repl ≡ Red
+       → RBI-state key value tree repl stack  -- two stages up
+   top-black : {tree repl : bt (Color ∧ A) } → {stack : List (bt (Color ∧ A))}  → stack ≡ tree ∷ []
+       → RBI-state key value tree repl stack
+
+record RBI {n : Level} {A : Set n} (key : ℕ) (value : A) (orig : bt (Color ∧ A) ) (stack : List (bt (Color ∧ A)))  : Set n where
+   field
+       tree repl : bt (Color ∧ A)
+       origti : treeInvariant orig
+       origrb : RBtreeInvariant orig
+       treerb : RBtreeInvariant tree     -- tree node te be replaced
+       replrb : RBtreeInvariant repl
+       si : stackInvariant key tree orig stack
+       state : RBI-state key value tree repl stack
+
+tr>-to-black : {n : Level} {A : Set n} {key : ℕ} {tree : bt (Color ∧ A)} → tr> key tree → tr> key (to-black tree)
+tr>-to-black {n} {A} {key} {leaf} tr = tt
+tr>-to-black {n} {A} {key} {node key₁ value tree tree₁} tr = tr
+
+tr<-to-black : {n : Level} {A : Set n} {key : ℕ} {tree : bt (Color ∧ A)} → tr< key tree → tr< key (to-black tree)
+tr<-to-black {n} {A} {key} {leaf} tr = tt
+tr<-to-black {n} {A} {key} {node key₁ value tree tree₁} tr = tr
+
+to-black-eq : {n : Level} {A : Set n}  (tree : bt (Color ∧ A)) → color tree ≡ Red → suc (black-depth tree) ≡ black-depth (to-black tree)
+to-black-eq {n} {A}  (leaf) ()
+to-black-eq {n} {A}  (node key₁ ⟪ Red , proj4 ⟫ tree tree₁) eq = refl
+to-black-eq {n} {A}  (node key₁ ⟪ Black , proj4 ⟫ tree tree₁) ()
+
+red-children-eq : {n : Level} {A : Set n}  {tree left right : bt (Color ∧ A)} → {key : ℕ} → {value : A} → {c : Color}
+   → tree ≡ node key ⟪ c , value ⟫ left right
+   → c ≡ Red
+   → RBtreeInvariant tree
+   → (black-depth tree ≡ black-depth left ) ∧ (black-depth tree ≡ black-depth right)
+red-children-eq {n} {A} {.(node key₁ ⟪ Red , value₁ ⟫ left right)} {left} {right} {.key₁} {.value₁} {Red} refl eq₁ rb2@(rb-red key₁ value₁ x x₁ x₂ rb rb₁) =
+  ⟪ ( begin
+        black-depth left ⊔ black-depth right ≡⟨ cong (λ k → black-depth left ⊔ k) (sym (RBtreeEQ rb2)) ⟩
+        black-depth left ⊔ black-depth left ≡⟨ ⊔-idem _ ⟩
+        black-depth left ∎  ) ,  (
+     begin
+        black-depth left ⊔ black-depth right ≡⟨ cong (λ k → k ⊔ black-depth right ) (RBtreeEQ rb2) ⟩
+        black-depth right ⊔ black-depth right ≡⟨ ⊔-idem _ ⟩
+        black-depth right ∎ ) ⟫ where open ≡-Reasoning
+red-children-eq {n} {A} {tree} {left} {right} {key} {value} {Black} eq () rb
+
+black-children-eq : {n : Level} {A : Set n}  {tree left right : bt (Color ∧ A)} → {key : ℕ} → {value : A} → {c : Color}
+   → tree ≡ node key ⟪ c , value ⟫ left right
+   → c ≡ Black
+   → RBtreeInvariant tree
+   → (black-depth tree ≡ suc (black-depth left) ) ∧ (black-depth tree ≡ suc (black-depth right))
+black-children-eq {n} {A} {.(node key₁ ⟪ Black , value₁ ⟫ left right)} {left} {right} {.key₁} {.value₁} {Black} refl eq₁ rb2@(rb-black key₁ value₁ x rb rb₁) =
+  ⟪ ( begin
+        suc (black-depth left ⊔ black-depth right) ≡⟨ cong (λ k → suc (black-depth left ⊔ k)) (sym (RBtreeEQ rb2)) ⟩
+        suc (black-depth left ⊔ black-depth left) ≡⟨ ⊔-idem _ ⟩
+        suc (black-depth left) ∎  ) ,  (
+     begin
+        suc (black-depth left ⊔ black-depth right) ≡⟨ cong (λ k → suc (k ⊔ black-depth right)) (RBtreeEQ rb2) ⟩
+        suc (black-depth right ⊔ black-depth right) ≡⟨ ⊔-idem _ ⟩
+        suc (black-depth right) ∎ ) ⟫ where open ≡-Reasoning
+black-children-eq {n} {A} {tree} {left} {right} {key} {value} {Red} eq () rb
+
+black-depth-cong  : {n : Level} (A : Set n)  {tree tree₁ : bt (Color ∧ A)}
+   → tree ≡ tree₁ → black-depth tree ≡ black-depth tree₁
+black-depth-cong  {n} A  {leaf} {leaf} refl = refl
+black-depth-cong {n} A {node key ⟪ Red , value ⟫ left right} {node .key ⟪ Red , .value ⟫ .left .right} refl
+   = cong₂ (λ j k → j ⊔ k ) (black-depth-cong A {left} {left} refl) (black-depth-cong A {right} {right} refl)
+black-depth-cong {n} A {node key ⟪ Black , value ⟫ left right} {node .key ⟪ Black , .value ⟫ .left .right} refl
+   = cong₂ (λ j k → suc (j ⊔ k) ) (black-depth-cong A {left} {left} refl) (black-depth-cong A {right} {right} refl)
+
+black-depth-resp  : {n : Level} (A : Set n)   (tree tree₁ : bt (Color ∧ A)) → {c1 c2 : Color}  { l1 l2 r1 r2 : bt (Color ∧ A)} {key1 key2 : ℕ} {value1 value2 : A}
+   → tree ≡ node key1 ⟪ c1 , value1 ⟫ l1 r1 → tree₁ ≡ node key2 ⟪ c2 , value2 ⟫ l2 r2
+   → color tree  ≡ color tree₁
+   → black-depth l1 ≡ black-depth l2 → black-depth r1 ≡ black-depth r2
+   → black-depth tree ≡ black-depth tree₁
+black-depth-resp  A _ _ {Black} {Black} refl refl refl eql eqr = cong₂ (λ j k → suc (j ⊔ k) ) eql eqr
+black-depth-resp  A _ _ {Red} {Red} refl refl refl eql eqr = cong₂ (λ j k → j ⊔ k ) eql eqr
+
+red-children-eq1 : {n : Level} {A : Set n}  {tree left right : bt (Color ∧ A)} → {key : ℕ} → {value : A} → {c : Color}
+   → tree ≡ node key ⟪ c , value ⟫ left right
+   → color tree ≡ Red
+   → RBtreeInvariant tree
+   → (black-depth tree ≡ black-depth left ) ∧ (black-depth tree ≡ black-depth right)
+red-children-eq1 {n} {A} {.(node key₁ ⟪ Red , value₁ ⟫ left right)} {left} {right} {.key₁} {.value₁} {Red} refl eq₁ rb2@(rb-red key₁ value₁ x x₁ x₂ rb rb₁) =
+  ⟪ ( begin
+        black-depth left ⊔ black-depth right ≡⟨ cong (λ k → black-depth left ⊔ k) (sym (RBtreeEQ rb2)) ⟩
+        black-depth left ⊔ black-depth left ≡⟨ ⊔-idem _ ⟩
+        black-depth left ∎  ) ,  (
+     begin
+        black-depth left ⊔ black-depth right ≡⟨ cong (λ k → k ⊔ black-depth right ) (RBtreeEQ rb2) ⟩
+        black-depth right ⊔ black-depth right ≡⟨ ⊔-idem _ ⟩
+        black-depth right ∎ ) ⟫ where open ≡-Reasoning
+red-children-eq1 {n} {A} {.(node key ⟪ Black , value ⟫ left right)} {left} {right} {key} {value} {Black} refl () rb
+
+black-children-eq1 : {n : Level} {A : Set n}  {tree left right : bt (Color ∧ A)} → {key : ℕ} → {value : A} → {c : Color}
+   → tree ≡ node key ⟪ c , value ⟫ left right
+   → color tree ≡ Black
+   → RBtreeInvariant tree
+   → (black-depth tree ≡ suc (black-depth left) ) ∧ (black-depth tree ≡ suc (black-depth right))
+black-children-eq1 {n} {A} {.(node key₁ ⟪ Black , value₁ ⟫ left right)} {left} {right} {.key₁} {.value₁} {Black} refl eq₁ rb2@(rb-black key₁ value₁ x rb rb₁) =
+  ⟪ ( begin
+        suc (black-depth left ⊔ black-depth right) ≡⟨ cong (λ k → suc (black-depth left ⊔ k)) (sym (RBtreeEQ rb2)) ⟩
+        suc (black-depth left ⊔ black-depth left) ≡⟨ ⊔-idem _ ⟩
+        suc (black-depth left) ∎  ) ,  (
+     begin
+        suc (black-depth left ⊔ black-depth right) ≡⟨ cong (λ k → suc (k ⊔ black-depth right)) (RBtreeEQ rb2) ⟩
+        suc (black-depth right ⊔ black-depth right) ≡⟨ ⊔-idem _ ⟩
+        suc (black-depth right) ∎ ) ⟫ where open ≡-Reasoning
+black-children-eq1 {n} {A} {.(node key ⟪ Red , value ⟫ left right)} {left} {right} {key} {value} {Red} refl () rb
+
+
+rbi-from-red-black : {n : Level } {A : Set n} → (n1 rp-left : bt (Color ∧ A)) → (kp : ℕ) → (vp : Color ∧ A)
+    → RBtreeInvariant n1 → RBtreeInvariant rp-left
+    → black-depth n1 ≡ black-depth rp-left
+    → color n1 ≡ Black → color rp-left ≡ Black →  ⟪ Red , proj2 vp ⟫ ≡ vp
+    → RBtreeInvariant (node kp vp n1 rp-left)
+rbi-from-red-black leaf leaf kp vp rb1 rbp deq ceq1 ceq2 ceq3
+    = subst (λ k → RBtreeInvariant (node kp k leaf leaf)) ceq3 (rb-red kp (proj2 vp)  refl refl refl rb-leaf rb-leaf)
+rbi-from-red-black leaf (node key ⟪ .Black , proj3 ⟫ trpl trpl₁) kp vp rb1 rbp deq ceq1 refl ceq3
+    = subst (λ k → RBtreeInvariant (node kp k _ _)) ceq3 (rb-red kp (proj2 vp) refl refl deq rb1 rbp)
+rbi-from-red-black (node key ⟪ .Black , proj3 ⟫ tn1 tn2) leaf kp vp rb1 rbp deq refl ceq2 ceq3
+    = subst (λ k → RBtreeInvariant (node kp k _ _)) ceq3 (rb-red kp (proj2 vp) refl refl deq rb1 rbp)
+rbi-from-red-black (node key ⟪ .Black , proj3 ⟫ tn1 tn2) (node key₁ ⟪ .Black , proj4 ⟫ trpl trpl₁) kp vp rb1 rbp deq refl refl ceq3
+  = subst (λ k → RBtreeInvariant (node kp k _ _)) ceq3 (rb-red kp (proj2 vp) refl refl deq rb1 rbp )
+
+⊔-succ : {m n : ℕ} → suc (m ⊔ n) ≡ suc m ⊔ suc n
+⊔-succ {m} {n} = refl
+
+
+--
+-- if we consider tree invariant, this may be much simpler and faster
+--
+stackToPG : {n : Level} {A : Set n} → {key : ℕ } → (tree orig : bt A )
+           →  (stack : List (bt A)) → stackInvariant key tree orig stack
+           → ( stack ≡ orig ∷ [] ) ∨ ( stack ≡ tree ∷ orig ∷ [] ) ∨ PG A key tree stack
+stackToPG {n} {A} {key} tree .tree .(tree ∷ []) s-nil = case1 refl
+stackToPG {n} {A} {key} tree .(node _ _ _ tree) .(tree ∷ node _ _ _ tree ∷ []) (s-right _ _ _ x s-nil) = case2 (case1 refl)
+stackToPG {n} {A} {key} tree .(node k2 v2 t5 (node k1 v1 t2 tree)) (tree ∷ node _ _ _ tree ∷ .(node k2 v2 t5 (node k1 v1 t2 tree) ∷ [])) (s-right tree (node k2 v2 t5 (node k1 v1 t2 tree)) t2 {k1} {v1} x (s-right (node k1 v1 t2 tree) (node k2 v2 t5 (node k1 v1 t2 tree)) t5 {k2} {v2} x₁ s-nil)) = case2 (case2
+    record {  parent = node k1 v1 t2 tree ;  grand = _ ; pg = s2-1s2p  x refl refl  ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig (tree ∷ node _ _ _ tree ∷ .(node k2 v2 t5 (node k1 v1 t2 tree) ∷ _)) (s-right tree orig t2 {k1} {v1} x (s-right (node k1 v1 t2 tree) orig t5 {k2} {v2} x₁ (s-right _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 t2 tree ;  grand = _ ; pg = s2-1s2p  x  refl refl  ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig (tree ∷ node _ _ _ tree ∷ .(node k2 v2 t5 (node k1 v1 t2 tree) ∷ _)) (s-right tree orig t2 {k1} {v1} x (s-right (node k1 v1 t2 tree) orig t5 {k2} {v2} x₁ (s-left _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 t2 tree ;  grand = _ ; pg = s2-1s2p  x refl refl  ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree .(node k2 v2 (node k1 v1 t1 tree) t2) .(tree ∷ node k1 v1 t1 tree ∷ node k2 v2 (node k1 v1 t1 tree) t2 ∷ []) (s-right _ _ t1 {k1} {v1} x (s-left _ _ t2 {k2} {v2} x₁ s-nil)) = case2 (case2
+    record {  parent = node k1 v1 t1 tree ;  grand = _ ; pg = s2-1sp2 x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig .(tree ∷ node k1 v1 t1 tree ∷ node k2 v2 (node k1 v1 t1 tree) t2 ∷ _) (s-right _ _ t1 {k1} {v1} x (s-left _ _ t2 {k2} {v2} x₁ (s-right _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 t1 tree ;  grand = _ ; pg = s2-1sp2 x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig .(tree ∷ node k1 v1 t1 tree ∷ node k2 v2 (node k1 v1 t1 tree) t2 ∷ _) (s-right _ _ t1 {k1} {v1} x (s-left _ _ t2 {k2} {v2} x₁ (s-left _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 t1 tree ;  grand = _ ; pg = s2-1sp2 x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree .(node _ _ tree _) .(tree ∷ node _ _ tree _ ∷ []) (s-left _ _ t1 {k1} {v1} x s-nil) = case2 (case1 refl)
+stackToPG {n} {A} {key} tree .(node _ _ _ (node k1 v1 tree t1)) .(tree ∷ node k1 v1 tree t1 ∷ node _ _ _ (node k1 v1 tree t1) ∷ []) (s-left _ _ t1 {k1} {v1} x (s-right _ _ _ x₁ s-nil)) = case2 (case2
+    record {  parent = node k1 v1 tree t1 ;  grand = _ ; pg =  s2-s12p x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig .(tree ∷ node k1 v1 tree t1 ∷ node _ _ _ (node k1 v1 tree t1) ∷ _) (s-left _ _ t1 {k1} {v1} x (s-right _ _ _ x₁ (s-right _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 tree t1 ;  grand = _ ; pg =  s2-s12p x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig .(tree ∷ node k1 v1 tree t1 ∷ node _ _ _ (node k1 v1 tree t1) ∷ _) (s-left _ _ t1 {k1} {v1} x (s-right _ _ _ x₁ (s-left _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 tree t1 ;  grand = _ ; pg =  s2-s12p x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree .(node _ _ (node k1 v1 tree t1) _) .(tree ∷ node k1 v1 tree t1 ∷ node _ _ (node k1 v1 tree t1) _ ∷ []) (s-left _ _ t1 {k1} {v1} x (s-left _ _ _ x₁ s-nil)) = case2 (case2
+    record {  parent = node k1 v1 tree t1 ;  grand = _ ; pg =  s2-s1p2 x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig .(tree ∷ node k1 v1 tree t1 ∷ node _ _ (node k1 v1 tree t1) _ ∷ _) (s-left _ _ t1 {k1} {v1} x (s-left _ _ _ x₁ (s-right _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 tree t1 ;  grand = _ ; pg =  s2-s1p2 x refl refl ; rest = _ ; stack=gp = refl } )
+stackToPG {n} {A} {key} tree orig .(tree ∷ node k1 v1 tree t1 ∷ node _ _ (node k1 v1 tree t1) _ ∷ _) (s-left _ _ t1 {k1} {v1} x (s-left _ _ _ x₁ (s-left _ _ _ x₂ si))) = case2 (case2
+    record {  parent = node k1 v1 tree t1 ;  grand = _ ; pg =  s2-s1p2 x refl refl ; rest = _ ; stack=gp = refl } )
+
+stackCase1 : {n : Level} {A : Set n} → {key : ℕ } → {tree orig : bt A }
+           →  {stack : List (bt A)} → stackInvariant key tree orig stack
+           →  stack ≡ orig ∷ [] → tree ≡ orig
+stackCase1 s-nil refl = refl
+
+pg-prop-1 : {n : Level} (A : Set n) → (key : ℕ) → (tree orig : bt A )
+           →  (stack : List (bt A)) → (pg : PG A key tree stack)
+           → (¬  PG.grand pg ≡ leaf ) ∧  (¬  PG.parent pg ≡ leaf)
+pg-prop-1 {_} A _ tree orig stack pg with PG.pg pg
+... | s2-s1p2 _ refl refl = ⟪ (λ () ) , ( λ () ) ⟫
+... | s2-1sp2 _ refl refl = ⟪ (λ () ) , ( λ () ) ⟫
+... | s2-s12p _ refl refl = ⟪ (λ () ) , ( λ () ) ⟫
+... | s2-1s2p _ refl refl = ⟪ (λ () ) , ( λ () ) ⟫
+
+popStackInvariant : {n : Level} {A : Set n} → (rest : List ( bt (Color ∧ A)))
+           → ( tree parent orig : bt (Color ∧ A)) →  (key : ℕ)
+           → stackInvariant key tree  orig ( tree ∷ parent ∷ rest )
+           → stackInvariant key parent orig (parent ∷ rest )
+popStackInvariant rest tree parent orig key (s-right .tree .orig tree₁ x si) = sc00 where
+     sc00 : stackInvariant key parent orig (parent ∷ rest )
+     sc00 with si-property1 si
+     ... | refl = si
+popStackInvariant rest tree parent orig key (s-left .tree .orig tree₁ x si) = sc00 where
+     sc00 : stackInvariant key parent orig (parent ∷ rest )
+     sc00 with si-property1 si
+     ... | refl = si
+
+
+siToTreeinvariant : {n : Level} {A : Set n} → (rest : List ( bt (Color ∧ A)))
+           → ( tree orig : bt (Color ∧ A)) →  (key : ℕ)
+           → treeInvariant orig
+           → stackInvariant key tree  orig ( tree ∷ rest )
+           → treeInvariant tree
+siToTreeinvariant .[] tree .tree key ti s-nil = ti
+siToTreeinvariant .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-right .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ leaf (node key₁ _ _ _) ∷ []) .(node key₁ _ _ _) .(node _ _ leaf (node key₁ _ _ _)) key (t-right _ key₁ x₁ x₂ x₃ ti) (s-right .(node key₁ _ _ _) .(node _ _ leaf (node key₁ _ _ _)) .leaf x s-nil) = ti
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) leaf ∷ []) .leaf .(node _ _ (node key₁ _ _ _) leaf) key (t-left key₁ _ x₁ x₂ x₃ ti) (s-right .leaf .(node _ _ (node key₁ _ _ _) leaf) .(node key₁ _ _ _) x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _) ∷ []) .(node key₂ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) key (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node key₂ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key₁ _ _ _) x s-nil) = ti₁
+siToTreeinvariant .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-right .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ ti₁ = ti₁
+... | t-left key₁ _ x₂ x₃ x₄ ti₁ = t-leaf
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ ti₁ ti₂ = ti₂
+siToTreeinvariant .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-left .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ ti₁ = ti₁
+... | t-left key₁ _ x₂ x₃ x₄ ti₁ = t-leaf
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ ti₁ ti₂ = ti₂
+siToTreeinvariant .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-left .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ leaf (node key₁ _ _ _) ∷ []) .leaf .(node _ _ leaf (node key₁ _ _ _)) key (t-right _ key₁ x₁ x₂ x₃ ti) (s-left .leaf .(node _ _ leaf (node key₁ _ _ _)) .(node key₁ _ _ _) x s-nil) = t-leaf
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) leaf ∷ []) .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) leaf) key (t-left key₁ _ x₁ x₂ x₃ ti) (s-left .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) leaf) .leaf x s-nil) = ti
+siToTreeinvariant .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _) ∷ []) .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) key (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-left .(node key₁ _ _ _) .(node _ _ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key₂ _ _ _) x s-nil) = ti
+siToTreeinvariant .(node _ _ tree tree₁ ∷ _) tree orig key ti (s-left .tree .orig tree₁ x si2@(s-right .(node _ _ tree tree₁) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ t = t-leaf
+... | t-left key₁ _ x₂ x₃ x₄ t = t
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ t t₁ = t
+siToTreeinvariant .(node _ _ tree tree₁ ∷ _) tree orig key ti (s-left .tree .orig tree₁ x si2@(s-left .(node _ _ tree tree₁) .orig tree₂ x₁ si)) with siToTreeinvariant _ _ _ _ ti si2
+... | t-single _ _ = t-leaf
+... | t-right _ key₁ x₂ x₃ x₄ t = t-leaf
+... | t-left key₁ _ x₂ x₃ x₄ t = t
+... | t-node key₁ _ key₂ x₂ x₃ x₄ x₅ x₆ x₇ t t₁ = t
+
+PGtoRBinvariant1 : {n : Level} {A : Set n}
+           → (tree orig : bt (Color ∧ A) )
+           → {key : ℕ }
+           →  (rb : RBtreeInvariant orig)
+           →  (stack : List (bt (Color ∧ A)))  → (si : stackInvariant key tree orig stack )
+           →  RBtreeInvariant tree
+PGtoRBinvariant1 tree .tree rb .(tree ∷ []) s-nil = rb
+PGtoRBinvariant1 tree orig rb (tree ∷ rest) (s-right .tree .orig tree₁ x si) with PGtoRBinvariant1 _ orig rb _ si
+... | rb-red _ value x₁ x₂ x₃ t t₁ = t₁
+... | rb-black _ value x₁ t t₁ = t₁
+PGtoRBinvariant1 tree orig rb (tree ∷ rest) (s-left .tree .orig tree₁ x si) with PGtoRBinvariant1 _ orig rb _ si
+... | rb-red _ value x₁ x₂ x₃ t t₁ = t
+... | rb-black _ value x₁ t t₁ = t
+
+RBI-child-replaced : {n : Level} {A : Set n} (tr : bt (Color ∧ A)) (key : ℕ) →  RBtreeInvariant tr → RBtreeInvariant (child-replaced key tr)
+RBI-child-replaced {n} {A} leaf key rbi = rbi
+RBI-child-replaced {n} {A} (node key₁ value tr tr₁) key rbi with <-cmp key key₁
+... | tri< a ¬b ¬c = RBtreeLeftDown _ _ rbi
+... | tri≈ ¬a b ¬c = rbi
+... | tri> ¬a ¬b c = RBtreeRightDown _ _ rbi
+
+--
+-- create RBT invariant after findRBT, continue to replaceRBT
+--
+createRBT : {n m : Level} {A : Set n } {t : Set m }
+ → (key : ℕ) (value : A)
+ → (tree0 : bt (Color ∧ A))
+ → RBtreeInvariant tree0
+ → treeInvariant tree0
+ → (tree1 : bt (Color ∧ A))
+ → (stack : List (bt (Color ∧ A)))
+ → stackInvariant key tree1 tree0 stack
+ → (tree1 ≡ leaf ) ∨ ( node-key tree1 ≡ just key )
+ → (exit : (stack : List ( bt (Color ∧ A))) (r : RBI key value tree0 stack ) → t ) → t
+createRBT {n} {m} {A} {t} key value orig rbi ti tree (x ∷ []) si P exit = crbt00 orig P refl where
+     crbt00 : (tree1 : bt (Color ∧ A)) → (tree ≡ leaf ) ∨ ( node-key tree ≡ just key ) → tree1 ≡ orig → t
+     crbt00 leaf P refl = exit (x ∷ []) record {
+         tree = leaf
+         ; repl = node key ⟪ Red , value ⟫ leaf leaf
+         ; origti = ti
+         ; origrb = rbi
+         ; treerb = rb-leaf
+         ; replrb = rb-red key value refl refl refl rb-leaf rb-leaf
+         ; si = subst (λ k → stackInvariant key k leaf _ ) crbt01 si
+         ; state = rotate leaf refl 
+         } where
+             crbt01 : tree ≡ leaf
+             crbt01 with si-property-last _ _ _ _ si | si-property1 si
+             ... | refl | refl = refl
+     crbt00 (node key₁ value₁ left right ) (case1 eq) refl with si-property-last _ _ _ _ si | si-property1 si
+     ... | refl | refl = ⊥-elim (bt-ne (sym eq))
+     crbt00 (node key₁ value₁ left right ) (case2 eq) refl with si-property-last _ _ _ _ si | si-property1 si
+     ... | refl | refl = exit (x ∷ []) record {
+         tree = node key₁ value₁ left right
+         ; repl = node key₁ ⟪ proj1 value₁ , value ⟫ left right
+         ; origti = ti
+         ; origrb = rbi
+         ; treerb = rbi
+         ; replrb = crbt03 value₁ rbi
+         ; si = si
+         ; state = rebuild refl (crbt01 value₁ ) (λ ()) 
+         }  where
+             crbt01 : (value₁ : Color ∧ A) → black-depth (node key₁ ⟪ proj1 value₁ , value ⟫ left right) ≡ black-depth (node key₁ value₁ left right)
+             crbt01 ⟪ Red , proj4 ⟫ = refl
+             crbt01 ⟪ Black , proj4 ⟫ = refl
+             crbt03 : (value₁ : Color ∧ A) → RBtreeInvariant (node key₁ value₁ left right) → RBtreeInvariant (node key₁ ⟪ proj1 value₁ , value ⟫ left right)
+             crbt03 ⟪ Red , proj4 ⟫ (rb-red .key₁ .proj4 x x₁ x₂ rbi rbi₁) = rb-red key₁ _ x x₁ x₂ rbi rbi₁
+             crbt03 ⟪ Black , proj4 ⟫ (rb-black .key₁ .proj4 x rbi rbi₁) = rb-black key₁ _ x rbi rbi₁
+             keq : ( just key₁ ≡ just key ) → key₁ ≡ key
+             keq refl = refl
+createRBT {n} {m} {A} {t} key value orig rbi ti tree (x ∷ leaf ∷ stack) si P exit = ⊥-elim (si-property-parent-node _ _ _ si refl)
+createRBT {n} {m} {A} {t} key value orig rbi ti tree sp@(x ∷ node kp vp pleft pright ∷ stack) si P exit = crbt00 tree P refl where
+     crbt00 : (tree1 : bt (Color ∧ A)) → (tree ≡ leaf ) ∨ ( node-key tree ≡ just key ) → tree1 ≡ tree → t
+     crbt00 leaf P refl = exit sp record {
+         tree = leaf
+         ; repl = node key ⟪ Red , value ⟫ leaf leaf
+         ; origti = ti
+         ; origrb = rbi
+         ; treerb = rb-leaf
+         ; replrb = rb-red key value refl refl refl rb-leaf rb-leaf
+         ; si = si
+         ; state = rotate leaf refl 
+         }
+     crbt00 (node key₁ value₁ left right ) (case1 eq) refl = ⊥-elim (bt-ne (sym eq))
+     crbt00 (node key₁ value₁ left right ) (case2 eq) refl with si-property-last _ _ _ _ si | si-property1 si
+     ... | eq1 | eq2 = exit sp record {
+         tree = node key₁ value₁ left right
+         ; repl = node key₁ ⟪ proj1 value₁ , value ⟫ left right
+         ; origti = ti
+         ; origrb = rbi
+         ; treerb = treerb
+         ; replrb = crbt03 value₁ treerb
+         ; si = si
+         ; state = rebuild refl (crbt01 value₁ ) (λ ()) 
+         }  where
+             crbt01 : (value₁ : Color ∧ A) → black-depth (node key₁ ⟪ proj1 value₁ , value ⟫ left right) ≡ black-depth (node key₁ value₁ left right)
+             crbt01 ⟪ Red , proj4 ⟫ = refl
+             crbt01 ⟪ Black , proj4 ⟫ = refl
+             crbt03 : (value₁ : Color ∧ A) → RBtreeInvariant (node key₁ value₁ left right) → RBtreeInvariant (node key₁ ⟪ proj1 value₁ , value ⟫ left right)
+             crbt03 ⟪ Red , proj4 ⟫ (rb-red .key₁ .proj4 x x₁ x₂ rbi rbi₁) = rb-red key₁ _ x x₁ x₂ rbi rbi₁
+             crbt03 ⟪ Black , proj4 ⟫ (rb-black .key₁ .proj4 x rbi rbi₁) = rb-black key₁ _ x rbi rbi₁
+             keq : ( just key₁ ≡ just key ) → key₁ ≡ key
+             keq refl = refl
+             treerb : RBtreeInvariant (node key₁ value₁ left right)
+             treerb = PGtoRBinvariant1 _ orig rbi _ si
+
+--
+--   rotate and rebuild replaceTree and rb-invariant
+--
+replaceRBP : {n m : Level} {A : Set n} {t : Set m}
+     → (key : ℕ) → (value : A)
+     → (orig : bt (Color ∧ A))
+     → (stack : List (bt (Color ∧ A)))
+     → (r : RBI key value orig stack )
+     → (next :  (stack1 : List (bt (Color ∧ A)))
+        → (r : RBI key value orig stack1 )
+        → length stack1 < length stack  → t )
+     → (exit : (stack1 : List (bt (Color ∧ A)))
+        →  stack1 ≡ (orig ∷ [])
+        →  RBI key value orig stack1
+        → t ) → t
+replaceRBP {n} {m} {A} {t} key value orig stack r next exit = replaceRBP1 where
+    -- we have no grand parent
+    -- eq : stack₁ ≡ RBI.tree r ∷ orig ∷ []
+    -- change parent color ≡ Black and exit
+    -- one level stack, orig is parent of repl
+    repl = RBI.repl r
+    insertCase4 :  (tr0 : bt (Color ∧ A)) → tr0 ≡ orig
+       → (eq : stack ≡ RBI.tree r ∷ orig ∷ [])
+       → ( color repl ≡ Red ) ∨ (color (RBI.tree r) ≡ color repl)
+       → stackInvariant key (RBI.tree r) orig stack
+       → t
+    insertCase4 leaf eq1 eq col si = ⊥-elim (rb04 eq eq1 si) where -- can't happen
+       rb04 : {stack : List ( bt ( Color ∧ A))} → stack ≡ RBI.tree r ∷ orig ∷ [] → leaf ≡ orig → stackInvariant key (RBI.tree r) orig stack →   ⊥
+       rb04  refl refl (s-right tree leaf tree₁ x si) = si-property2 _ (s-right tree leaf tree₁ x si) refl
+       rb04  refl refl (s-left tree₁ leaf tree x si) = si-property2 _  (s-left tree₁ leaf tree x si) refl
+    insertCase4  tr0@(node key₁ value₁ left right) refl eq col si with <-cmp key key₁
+    ... | tri< a ¬b ¬c = rb07 col where
+       rb04 : stackInvariant key (RBI.tree r) orig stack → stack ≡ RBI.tree r ∷ orig ∷ [] → tr0 ≡ orig → left ≡ RBI.tree r
+       rb04 (s-left tree₁ .(node key₁ value₁ left right) tree {key₂} x s-nil) refl refl = refl
+       rb04 (s-right tree .(node key₁ _ tree₁ tree) tree₁ x s-nil) refl refl with si-property1 si
+       ... | refl = ⊥-elim ( nat-<> x a  )
+       rb06 : black-depth repl ≡ black-depth right
+       rb06 = ?
+       rb08 :  (color (RBI.tree r) ≡ color repl) → RBtreeInvariant (node key₁ value₁ repl right)
+       rb08 ceq with proj1 value₁ in coeq
+       ... | Red = subst (λ k → RBtreeInvariant (node key₁ k repl right)) (cong (λ k → ⟪ k , _ ⟫) (sym coeq) )
+           (rb-red _ (proj2 value₁) rb09 (proj2 (RBtreeChildrenColorBlack _ _ (RBI.origrb r) coeq)) rb06 (RBI.replrb r)
+               (RBtreeRightDown _ _ (RBI.origrb r))) where
+           rb09 : color repl ≡ Black
+           rb09 = trans (trans (sym ceq) (sym (cong color (rb04 si eq refl) ))) (proj1 (RBtreeChildrenColorBlack _ _ (RBI.origrb r) coeq))
+       ... | Black = subst (λ k → RBtreeInvariant (node key₁ k repl right)) (cong (λ k → ⟪ k , _ ⟫) (sym coeq) )
+           (rb-black _ (proj2 value₁) rb06 (RBI.replrb r) (RBtreeRightDown _ _ (RBI.origrb r)))
+       rb07 : ( color repl ≡ Red ) ∨ (color (RBI.tree r) ≡ color repl) → t
+       rb07 (case2 cc ) = exit  (orig ∷ []) refl record {
+         tree = orig
+         ; repl = node key₁ value₁ repl right
+         ; origti = RBI.origti r
+         ; origrb = RBI.origrb r
+         ; treerb = RBI.origrb r
+         ; replrb = rb08 cc
+         ; si = s-nil
+         ; state = top-black  refl 
+         }
+       rb07 (case1 repl-red) = exit  (orig ∷ []) refl record {
+         tree = orig
+         ; repl = to-black (node key₁ value₁ repl right)
+         ; origti = RBI.origti r
+         ; origrb = RBI.origrb r
+         ; treerb = RBI.origrb r
+         ; replrb = rb-black _ _ rb06 (RBI.replrb r) (RBtreeRightDown _ _ (RBI.origrb r))
+         ; si = s-nil
+         ; state = top-black  refl 
+         }
+    ... | tri≈ ¬a b ¬c = ⊥-elim ( si-property-pne _ _ stack eq si b ) -- can't happen
+    ... | tri> ¬a ¬b c = rb07 col where
+       rb04 : stackInvariant key (RBI.tree r) orig stack → stack ≡ RBI.tree r ∷ orig ∷ [] → tr0 ≡ orig → right ≡ RBI.tree r
+       rb04 (s-right tree .(node key₁ _ tree₁ tree) tree₁ x s-nil) refl refl = refl
+       rb04 (s-left tree₁ .(node key₁ value₁ left right) tree {key₂} x si) refl refl with si-property1 si
+       ... | refl = ⊥-elim ( nat-<> x c  )
+       rb06 : black-depth repl ≡ black-depth left
+       rb06 = ? 
+       rb08 :  (color (RBI.tree r) ≡ color repl) → RBtreeInvariant (node key₁ value₁ left repl )
+       rb08 ceq with proj1 value₁ in coeq
+       ... | Red = subst (λ k → RBtreeInvariant (node key₁ k left repl )) (cong (λ k → ⟪ k , _ ⟫) (sym coeq) )
+           (rb-red _ (proj2 value₁) (proj1 (RBtreeChildrenColorBlack _ _ (RBI.origrb r) coeq)) rb09 (sym rb06)
+               (RBtreeLeftDown _ _ (RBI.origrb r))(RBI.replrb r)) where
+           rb09 : color repl ≡ Black
+           rb09 = trans (trans (sym ceq) (sym (cong color (rb04 si eq refl) ))) (proj2 (RBtreeChildrenColorBlack _ _ (RBI.origrb r) coeq))
+       ... | Black = subst (λ k → RBtreeInvariant (node key₁ k left repl )) (cong (λ k → ⟪ k , _ ⟫) (sym coeq) )
+           (rb-black _ (proj2 value₁) (sym rb06)  (RBtreeLeftDown _ _ (RBI.origrb r)) (RBI.replrb r))
+       rb07 : ( color repl ≡ Red ) ∨ (color (RBI.tree r) ≡ color repl) → t
+       rb07 (case2 cc ) = exit  (orig ∷ []) refl record {
+         tree = orig
+         ; repl = node key₁ value₁ left repl
+         ; origti = RBI.origti r
+         ; origrb = RBI.origrb r
+         ; treerb = RBI.origrb r
+         ; replrb = rb08 cc
+         ; si = s-nil
+         ; state = top-black  refl 
+         }
+       rb07 (case1 repl-red ) = exit  (orig ∷ [])  refl record {
+         tree = orig
+         ; repl = to-black (node key₁ value₁ left repl)
+         ; origti = RBI.origti r
+         ; origrb = RBI.origrb r
+         ; treerb = RBI.origrb r
+         ; replrb = rb-black _ _ (sym rb06) (RBtreeLeftDown _ _ (RBI.origrb r)) (RBI.replrb r)
+         ; si = s-nil
+         ; state = top-black refl 
+         }
+    rebuildCase : (ceq : color (RBI.tree r) ≡ color repl)
+       → (bdepth-eq : black-depth repl ≡ black-depth (RBI.tree r))
+       → (¬ RBI.tree r ≡ leaf) → t
+    rebuildCase ceq bdepth-eq ¬leaf with stackToPG (RBI.tree r) orig stack (RBI.si r)
+    ... | case1 x = exit stack x r  where  -- single node case
+        rb00 : stack ≡ orig ∷ [] → orig ≡ RBI.tree r
+        rb00 refl = si-property1 (RBI.si r)
+    ... | case2 (case1 x) = insertCase4 orig refl x (case2 ceq) (RBI.si r)   -- one level stack, orig is parent of repl
+    ... | case2 (case2 pg) = rebuildCase1 pg where
+       rb00 : (pg : PG (Color ∧ A) key (RBI.tree r) stack) → stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+       rb00 pg = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+       treerb : (pg : PG (Color ∧ A) key (RBI.tree r) stack) → RBtreeInvariant (PG.parent pg)
+       treerb pg = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (rb00 pg))
+       rb08 : (pg : PG (Color ∧ A) key (RBI.tree r) stack) → treeInvariant (PG.parent pg)
+       rb08 pg = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (rb00 pg))
+       rebuildCase1 : (PG (Color ∧ A) key (RBI.tree r) stack) → t
+       rebuildCase1 pg with PG.pg pg
+       ... | s2-s1p2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = rebuildCase2 where
+          rebuildCase2 : t
+          rebuildCase2 = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+              tree = PG.parent pg
+              ; repl = rb01
+              ; origti = RBI.origti r
+              ; origrb = RBI.origrb r
+              ; treerb = treerb pg
+              ; replrb = rb02
+              ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+              ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))  
+             } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+               rb01 : bt (Color ∧ A)
+               rb01 = node kp vp repl n1
+               rb03 : black-depth n1 ≡ black-depth repl
+               rb03 = ?
+               rb02 : RBtreeInvariant rb01
+               rb02 with subst (λ k → RBtreeInvariant k) x (treerb pg)
+               ... | rb-red .kp value cx cx₁ ex₂ t t₁ = rb-red kp value (trans (sym ceq) cx) cx₁ (sym rb03) (RBI.replrb r) t₁
+               ... | rb-black .kp value ex t t₁ = rb-black kp value (sym rb03) (RBI.replrb r) t₁
+               rb05 : treeInvariant (node kp vp (RBI.tree r) n1 )
+               rb05 = subst (λ k → treeInvariant k) x (rb08 pg)
+               rb04 : key < kp
+               rb04 = lt
+               rb06 : black-depth rb01 ≡ black-depth (PG.parent pg)
+               rb06 = trans (rb07 vp) ( cong black-depth (sym x) ) where
+                   rb07 : (vp : Color ∧ A) → black-depth (node kp vp repl n1) ≡ black-depth (node kp vp (RBI.tree r) n1 )
+                   rb07 ⟪ Black  , proj4 ⟫ = cong (λ k → suc (k ⊔ black-depth n1 )) bdepth-eq
+                   rb07 ⟪ Red  , proj4 ⟫ = cong (λ k → (k ⊔ black-depth n1  )) bdepth-eq
+       ... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = rebuildCase2 where
+          rebuildCase2 : t
+          rebuildCase2 = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+              tree = PG.parent pg
+              ; repl = rb01
+              ; origti = RBI.origti r
+              ; origrb = RBI.origrb r
+              ; treerb = treerb pg
+              ; replrb = rb02
+              ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+              ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) 
+             } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+               rb01 : bt (Color ∧ A)
+               rb01 = node kp vp n1 repl
+               rb03 : black-depth n1 ≡ black-depth repl
+               rb03 = ?
+               rb02 : RBtreeInvariant rb01
+               rb02 with subst (λ k → RBtreeInvariant k) x (treerb pg)
+               ... | rb-red .kp value cx cx₁ ex₂ t t₁ = rb-red kp value cx (trans (sym ceq) cx₁) rb03 t (RBI.replrb r)
+               ... | rb-black .kp value ex t t₁ = rb-black kp value rb03 t (RBI.replrb r)
+               rb05 : treeInvariant (node kp vp n1 (RBI.tree r) )
+               rb05 = subst (λ k → treeInvariant k) x (rb08 pg)
+               rb04 : kp < key
+               rb04 = lt
+               rb06 : black-depth rb01 ≡ black-depth (PG.parent pg)
+               rb06 = trans (rb07 vp) ( cong black-depth (sym x) ) where
+                   rb07 : (vp : Color ∧ A) → black-depth (node kp vp n1 repl) ≡ black-depth (node kp vp n1 (RBI.tree r))
+                   rb07 ⟪ Black  , proj4 ⟫ = cong (λ k → suc (black-depth n1 ⊔ k)) bdepth-eq
+                   rb07 ⟪ Red  , proj4 ⟫ = cong (λ k → (black-depth n1 ⊔ k)) bdepth-eq
+       ... | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = rebuildCase2 where
+          rebuildCase2 : t
+          rebuildCase2 = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+              tree = PG.parent pg
+              ; repl = rb01
+              ; origti = RBI.origti r
+              ; origrb = RBI.origrb r
+              ; treerb = treerb pg
+              ; replrb = rb02
+              ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+              ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) 
+             } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+               rb01 : bt (Color ∧ A)
+               rb01 = node kp vp repl n1
+               rb03 : black-depth n1 ≡ black-depth repl
+               rb03 = ?
+               rb02 : RBtreeInvariant rb01
+               rb02 with subst (λ k → RBtreeInvariant k) x (treerb pg)
+               ... | rb-red .kp value cx cx₁ ex₂ t t₁ = rb-red kp value (trans (sym ceq) cx) cx₁ (sym rb03) (RBI.replrb r) t₁
+               ... | rb-black .kp value ex t t₁ = rb-black kp value (sym rb03) (RBI.replrb r) t₁
+               rb05 : treeInvariant (node kp vp (RBI.tree r) n1)
+               rb05 = subst (λ k → treeInvariant k) x (rb08 pg)
+               rb04 : key < kp
+               rb04 = lt
+               rb06 : black-depth rb01 ≡ black-depth (PG.parent pg)
+               rb06 = trans (rb07 vp) ( cong black-depth (sym x) ) where
+                   rb07 : (vp : Color ∧ A) → black-depth (node kp vp repl n1) ≡ black-depth (node kp vp (RBI.tree r) n1)
+                   rb07 ⟪ Black  , proj4 ⟫ = cong (λ k → suc (k ⊔ black-depth n1 )) bdepth-eq
+                   rb07 ⟪ Red  , proj4 ⟫ = cong (λ k → (k ⊔ black-depth n1 ))  bdepth-eq
+       ... | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = rebuildCase2 where
+          rebuildCase2 : t
+          rebuildCase2 = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+              tree = PG.parent pg
+              ; repl = rb01
+              ; origti = RBI.origti r
+              ; origrb = RBI.origrb r
+              ; treerb = treerb pg
+              ; replrb = rb02
+              ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+              ; state = rebuild (cong color x) rb06 (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) 
+             } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+               rb01 : bt (Color ∧ A)
+               rb01 = node kp vp n1 repl
+               rb03 : black-depth n1 ≡ black-depth repl
+               rb03 = ?
+               rb02 : RBtreeInvariant rb01
+               rb02 with subst (λ k → RBtreeInvariant k) x (treerb pg)
+               ... | rb-red .kp value cx cx₁ ex₂ t t₁ = rb-red kp value cx (trans (sym ceq) cx₁) rb03 t (RBI.replrb r)
+               ... | rb-black .kp value ex t t₁ = rb-black kp value rb03 t (RBI.replrb r)
+               rb05 : treeInvariant (node kp vp n1 (RBI.tree r))
+               rb05 = subst (λ k → treeInvariant k) x (rb08 pg)
+               rb04 : kp < key
+               rb04 = si-property-> ¬leaf rb05 (subst (λ k → stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ k ∷ PG.grand pg ∷ PG.rest pg)) x (rb00 pg))
+               rb06 : black-depth rb01 ≡ black-depth (PG.parent pg)
+               rb06 = trans (rb07 vp) ( cong black-depth (sym x) ) where
+                   rb07 : (vp : Color ∧ A) → black-depth (node kp vp n1 repl) ≡ black-depth (node kp vp n1 (RBI.tree r))
+                   rb07 ⟪ Black  , proj4 ⟫ = cong (λ k → suc (black-depth n1 ⊔ k)) bdepth-eq
+                   rb07 ⟪ Red  , proj4 ⟫ = cong (λ k → (black-depth n1 ⊔ k)) bdepth-eq
+    --
+    -- both parent and uncle are Red, rotate then goto rebuild
+    --
+    insertCase5 : (repl1 : bt (Color ∧ A)) → repl1 ≡ repl
+       → (pg : PG (Color ∧ A) key (RBI.tree r) stack)
+       → color repl ≡ Red → color (PG.uncle pg) ≡ Black → color (PG.parent pg) ≡ Red → t
+    insertCase5 leaf eq pg repl-red uncle-black pcolor = ⊥-elim ( rb00 repl repl-red (cong color (sym eq))) where
+        rb00 : (repl : bt (Color ∧ A)) → color repl ≡ Red → color repl ≡ Black → ⊥
+        rb00 (node key ⟪ Black , proj4 ⟫ repl repl₁) () eq1
+        rb00 (node key ⟪ Red , proj4 ⟫ repl repl₁) eq ()
+    insertCase5 (node rkey vr rp-left rp-right) eq pg repl-red uncle-black pcolor = insertCase51 where
+        rb00 : stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+        rb00 = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+        rb15 : suc (length (PG.rest pg)) < length stack
+        rb15 = begin
+              suc (suc (length (PG.rest pg))) ≤⟨ <-trans (n<1+n _) (n<1+n _) ⟩
+              length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
+              length stack ∎
+                 where open ≤-Reasoning
+        rb02 : RBtreeInvariant (PG.grand pg)
+        rb02 = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))
+        rb09 : RBtreeInvariant (PG.parent pg)
+        rb09 = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ rb00)
+        rb08 : treeInvariant (PG.parent pg)
+        rb08 = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00)
+
+        insertCase51 : t
+        insertCase51 with PG.pg pg
+        ... | s2-s1p2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase52 where
+          insertCase52 : t
+          insertCase52 = next (PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.grand pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = rb02
+            ; replrb = subst (λ k → RBtreeInvariant k) rb10 (rb-black _ _ rb18 (RBI.replrb r) (rb-red _ _ rb16 uncle-black rb19 rb06 rb05))
+            ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+            ; state = rebuild (trans (cong color x₁) (cong proj1 (sym rb14))) rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) 
+           } rb15 where
+            rb01 : bt (Color ∧ A)
+            rb01 = to-black (node kp vp (node rkey vr rp-left rp-right) (to-red (node kg vg n1 (PG.uncle pg))))
+            rb04 : key < kp
+            rb04 = lt
+            rb16 : color n1 ≡ Black
+            rb16 = proj2 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) x rb09) (trans (cong color (sym x)) pcolor))
+            rb13 : ⟪ Red , proj2 vp ⟫ ≡ vp
+            rb13 with subst (λ k → color k ≡ Red ) x pcolor
+            ... | refl = refl
+            rb14 : ⟪ Black , proj2 vg ⟫ ≡ vg
+            rb14 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02) (case1 pcolor)
+            ... | refl = refl
+            rb10 : node kp ⟪ Black , proj2 vp ⟫ repl (node kg ⟪ Red , proj2 vg ⟫ n1 (PG.uncle pg)) ≡ rb01
+            rb10 = begin
+               to-black (node kp vp repl (to-red (node kg vg n1 (PG.uncle pg)))) ≡⟨ cong (λ k → node _ _ k _) (sym eq) ⟩
+               rb01 ∎ where open ≡-Reasoning
+            rb12 : node kg ⟪ Black , proj2 vg ⟫ (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) (PG.uncle pg) ≡ PG.grand pg
+            rb12 = begin
+                 node kg ⟪ Black , proj2 vg ⟫ (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) (PG.uncle pg)
+                    ≡⟨ cong₂ (λ j k → node kg j (node kp k (RBI.tree r) n1) (PG.uncle pg) ) rb14 rb13 ⟩
+                 node kg vg _ (PG.uncle pg) ≡⟨ cong (λ k → node _ _ k _) (sym x) ⟩
+                 node kg vg (PG.parent pg) (PG.uncle pg) ≡⟨ sym x₁ ⟩
+                 PG.grand pg ∎ where open ≡-Reasoning
+            rb05 : RBtreeInvariant (PG.uncle pg)
+            rb05 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02)
+            rb06 : RBtreeInvariant n1
+            rb06 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x rb09)
+            rb19 : black-depth n1 ≡ black-depth (PG.uncle pg)
+            rb19 = trans (sym ( proj2 (red-children-eq x (sym (cong proj1 rb13))  rb09) )) (RBtreeEQ (subst (λ k → RBtreeInvariant k) x₁ rb02))
+            rb18 : black-depth repl ≡ black-depth n1 ⊔ black-depth (PG.uncle pg)
+            rb18 = ?
+            rb17 : suc (black-depth (node rkey vr rp-left rp-right) ⊔ (black-depth n1 ⊔ black-depth (PG.uncle pg))) ≡ black-depth (PG.grand pg)
+            rb17 = ?
+        ... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase52 where
+          insertCase52 : t
+          insertCase52 = next (PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.grand pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = rb02
+            ; replrb = rb10
+            ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+            ; state = rebuild rb33 rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) 
+           } rb15 where
+                -- inner case, repl  is decomposed
+                -- lt          : kp < key
+                -- x           : PG.parent pg ≡ node kp vp n1 (RBI.tree r)
+                -- x₁          : PG.grand pg ≡ node kg vg (PG.parent pg) (PG.uncle pg)
+                -- eq          : node rkey vr rp-left rp-right ≡ RBI.repl r
+            rb01 : bt (Color ∧ A)
+            rb01 = to-black (node rkey vr (node kp vp n1 rp-left) (to-red (node kg vg rp-right (PG.uncle pg))))
+            rb04 : kp < key
+            rb04 = lt
+            rb21 : key < kg   -- this can be a part of ParentGand relation
+            rb21 = si-property-< (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → treeInvariant k ) x₁ (siToTreeinvariant _ _ _ _ (RBI.origti r)
+                 (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))))
+                 (subst (λ k → stackInvariant key _ orig (PG.parent pg ∷ k ∷ PG.rest pg)) x₁ (popStackInvariant _ _ _ _ _ rb00))
+            rb16 : color n1 ≡ Black
+            rb16 = proj1 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) x rb09) (trans (cong color (sym x)) pcolor))
+            rb13 : ⟪ Red , proj2 vp ⟫ ≡ vp
+            rb13 with subst (λ k → color k ≡ Red ) x pcolor
+            ... | refl = refl
+            rb14 : ⟪ Black , proj2 vg ⟫ ≡ vg
+            rb14 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02) (case1 pcolor)
+            ... | refl = refl
+            rb33 : color (PG.grand pg) ≡ Black
+            rb33 = subst (λ k → color k ≡ Black ) (sym x₁) (sym (cong proj1 rb14))
+            rb23 :  vr ≡ ⟪ Red , proj2 vr ⟫
+            rb23 with subst (λ k → color k ≡ Red ) (sym eq) repl-red
+            ... | refl = refl
+            rb20 : color rp-right ≡ Black
+            rb20 = proj2 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r) ) (cong proj1 rb23))
+            rb24 : node kg ⟪ Black , proj2 vg ⟫ (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r)) (PG.uncle pg) ≡ PG.grand pg
+            rb24 = trans (trans (cong₂ (λ j k → node kg j (node kp k n1 (RBI.tree r)) (PG.uncle pg)) rb14 rb13 ) (cong (λ k → node kg vg k (PG.uncle pg)) (sym x))) (sym x₁)
+            rb25 : node rkey ⟪ Black , proj2 vr ⟫ (node kp ⟪ Red , proj2 vp ⟫ n1 rp-left) (node kg ⟪ Red , proj2 vg ⟫ rp-right (PG.uncle pg)) ≡ rb01
+            rb25 = begin
+                node rkey ⟪ Black , proj2 vr ⟫ (node kp ⟪ Red , proj2 vp ⟫ n1 rp-left) (node kg ⟪ Red , proj2 vg ⟫ rp-right (PG.uncle pg))
+                     ≡⟨ cong (λ k → node _ _ (node kp k  n1 rp-left) _ ) rb13 ⟩
+                node rkey ⟪ Black , proj2 vr ⟫ (node kp vp n1 rp-left) (node kg ⟪ Red , proj2 vg ⟫ rp-right (PG.uncle pg))  ≡⟨ refl  ⟩
+                rb01 ∎ where open ≡-Reasoning
+            rb05 : RBtreeInvariant (PG.uncle pg)
+            rb05 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02)
+            rb06 : RBtreeInvariant n1
+            rb06 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x rb09)
+            rb26 : RBtreeInvariant rp-left
+            rb26 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r))
+            rb28 : RBtreeInvariant rp-right
+            rb28 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r))
+            rb31 : RBtreeInvariant (node rkey vr rp-left rp-right )
+            rb31 = subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r)
+            rb18 : black-depth rp-right ≡ black-depth (PG.uncle pg)
+            rb18 = ?
+            rb27 : black-depth n1 ≡ black-depth rp-left
+            rb27 = ?
+            rb19 : black-depth (node kp vp n1 rp-left) ≡ black-depth rp-right ⊔ black-depth (PG.uncle pg)
+            rb19 = begin
+                black-depth (node kp vp n1 rp-left) ≡⟨ black-depth-resp A (node kp vp n1 rp-left) (node kp vp rp-left rp-left)  refl refl refl rb27 refl ⟩
+                black-depth (node kp vp rp-left rp-left) ≡⟨ black-depth-resp A (node kp vp rp-left rp-left) (node rkey vr rp-left rp-right)
+                     refl refl (trans (sym (cong proj1 rb13)) (sym (cong proj1 rb23))) refl (RBtreeEQ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r))) ⟩
+                black-depth (node rkey vr rp-left rp-right) ≡⟨ black-depth-cong A eq ⟩
+                black-depth (RBI.repl r) ≡⟨ proj2 (red-children-eq1 (sym eq) repl-red (RBI.replrb r)) ⟩
+                black-depth rp-right ≡⟨ sym ( ⊔-idem _ ) ⟩
+                black-depth rp-right ⊔ black-depth rp-right ≡⟨ cong (λ k → black-depth rp-right ⊔ k) rb18 ⟩
+                black-depth rp-right ⊔ black-depth (PG.uncle pg) ∎
+                  where open ≡-Reasoning
+            rb29 : color n1 ≡ Black
+            rb29 = proj1 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) x rb09) (sym (cong proj1 rb13)) )
+            rb30 : color rp-left ≡ Black
+            rb30 = proj1 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r)) (cong proj1 rb23))
+            rb32 : suc (black-depth (PG.uncle pg)) ≡ black-depth (PG.grand pg)
+            rb32 = sym (proj2 ( black-children-eq1 x₁ rb33 rb02 ))
+            rb10 : RBtreeInvariant (node rkey ⟪ Black , proj2 vr ⟫ (node kp vp n1 rp-left) (node kg ⟪ Red , proj2 vg ⟫ rp-right (PG.uncle pg)))
+            rb10 = rb-black _ _ rb19 (rbi-from-red-black _ _ kp vp rb06 rb26 rb27 rb29 rb30 rb13) (rb-red _ _ rb20 uncle-black rb18 rb28 rb05)
+            rb17 : suc (black-depth (node kp vp n1 rp-left) ⊔ (black-depth rp-right ⊔ black-depth (PG.uncle pg))) ≡ black-depth (PG.grand pg)
+            rb17 = begin
+                 suc (black-depth (node kp vp n1 rp-left) ⊔ (black-depth rp-right ⊔ black-depth (PG.uncle pg))) ≡⟨ cong (λ k → suc (k ⊔ _)) rb19 ⟩
+                 suc ((black-depth rp-right ⊔ black-depth (PG.uncle pg)) ⊔ (black-depth rp-right ⊔ black-depth (PG.uncle pg))) ≡⟨ cong suc ( ⊔-idem _) ⟩
+                 suc (black-depth rp-right ⊔ black-depth (PG.uncle pg))  ≡⟨ cong (λ k → suc (k ⊔ _)) rb18 ⟩
+                 suc (black-depth (PG.uncle pg) ⊔ black-depth (PG.uncle pg)) ≡⟨ cong suc (⊔-idem _) ⟩
+                 suc (black-depth (PG.uncle pg))  ≡⟨ rb32 ⟩
+                 black-depth (PG.grand pg) ∎
+                 where open ≡-Reasoning
+        ... | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase52 where
+          insertCase52 : t
+          insertCase52 = next (PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.grand pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = rb02
+            ; replrb = rb10
+            ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+            ; state = rebuild rb33 rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) 
+           } rb15 where
+                -- inner case, repl  is decomposed
+                -- lt          : key < kp
+                -- x           : PG.parent pg ≡ node kp vp (RBI.tree r) n1
+                -- x₁          : PG.grand pg ≡ node kg vg (PG.uncle pg) (PG.parent pg)
+                -- eq          : node rkey vr rp-left rp-right ≡ RBI.repl r
+            rb01 : bt (Color ∧ A)
+            rb01 = to-black (node rkey vr (to-red (node kg vg (PG.uncle pg) rp-left )) (node kp vp rp-right n1))
+            rb04 : key < kp
+            rb04 = lt
+            rb21 : kg < key   -- this can be a part of ParentGand relation
+            rb21 = si-property-> (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → treeInvariant k ) x₁ (siToTreeinvariant _ _ _ _ (RBI.origti r)
+                 (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))))
+                 (subst (λ k → stackInvariant key _ orig (PG.parent pg ∷ k ∷ PG.rest pg)) x₁ (popStackInvariant _ _ _ _ _ rb00))
+            rb16 : color n1 ≡ Black
+            rb16 = proj2 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) x rb09) (trans (cong color (sym x)) pcolor))
+            rb13 : ⟪ Red , proj2 vp ⟫ ≡ vp
+            rb13 with subst (λ k → color k ≡ Red ) x pcolor
+            ... | refl = refl
+            rb14 : ⟪ Black , proj2 vg ⟫ ≡ vg
+            rb14 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02) (case2 pcolor)
+            ... | refl = refl
+            rb33 : color (PG.grand pg) ≡ Black
+            rb33 = subst (λ k → color k ≡ Black ) (sym x₁) (sym (cong proj1 rb14))
+            rb23 :  vr ≡ ⟪ Red , proj2 vr ⟫
+            rb23 with subst (λ k → color k ≡ Red ) (sym eq) repl-red
+            ... | refl = refl
+            rb20 : color rp-right ≡ Black
+            rb20 = proj2 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r) ) (cong proj1 rb23))
+            rb24 : node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) ≡ PG.grand pg
+            rb24 = begin
+               node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1)
+                   ≡⟨ cong₂ (λ j k → node kg j (PG.uncle pg) (node kp k (RBI.tree r) n1) ) rb14 rb13 ⟩
+               node kg vg (PG.uncle pg) (node kp vp (RBI.tree r) n1) ≡⟨ cong (λ k → node kg vg (PG.uncle pg) k ) (sym x) ⟩
+               node kg vg (PG.uncle pg) (PG.parent pg) ≡⟨ sym x₁ ⟩
+               PG.grand pg ∎ where open ≡-Reasoning
+            rb25 : node rkey ⟪ Black , proj2 vr ⟫ (node kg ⟪ Red , proj2 vg ⟫ (PG.uncle pg) rp-left) (node kp ⟪ Red , proj2 vp ⟫ rp-right n1) ≡ rb01
+            rb25 = begin
+                node rkey ⟪ Black , proj2 vr ⟫ (node kg ⟪ Red , proj2 vg ⟫ (PG.uncle pg) rp-left) (node kp ⟪ Red , proj2 vp ⟫ rp-right n1)
+                        ≡⟨ cong (λ k → node rkey ⟪ Black , proj2 vr ⟫ (node kg ⟪ Red , proj2 vg ⟫ (PG.uncle pg) rp-left) (node kp k rp-right n1)) rb13  ⟩
+                node rkey ⟪ Black , proj2 vr ⟫ (node kg ⟪ Red , proj2 vg ⟫ (PG.uncle pg) rp-left) (node kp vp rp-right n1)  ≡⟨ refl ⟩
+                rb01 ∎ where open ≡-Reasoning
+            rb05 : RBtreeInvariant (PG.uncle pg)
+            rb05 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02)
+            rb06 : RBtreeInvariant n1
+            rb06 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x rb09)
+            rb26 : RBtreeInvariant rp-left
+            rb26 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r))
+            rb28 : RBtreeInvariant rp-right
+            rb28 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r))
+            rb31 : RBtreeInvariant (node rkey vr rp-left rp-right )
+            rb31 = subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r)
+            rb18 : black-depth (PG.uncle pg) ≡ black-depth rp-left
+            rb18 = ?
+            rb27 : black-depth rp-right ≡ black-depth n1
+            rb27 = ?
+            rb19 : black-depth (PG.uncle pg) ⊔ black-depth rp-left ≡ black-depth (node kp vp rp-right n1)
+            rb19 = sym ( begin
+                black-depth (node kp vp rp-right n1)  ≡⟨ black-depth-resp A (node kp vp rp-right n1) (node kp vp rp-right rp-right)  refl refl refl refl (sym rb27) ⟩
+                black-depth (node kp vp rp-right rp-right) ≡⟨ black-depth-resp A (node kp vp rp-right rp-right) (node rkey vr rp-left rp-right)
+                     refl refl (trans (sym (cong proj1 rb13)) (sym (cong proj1 rb23))) (sym (RBtreeEQ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r)))) refl ⟩
+                black-depth (node rkey vr rp-left rp-right) ≡⟨ black-depth-cong A eq ⟩
+                black-depth (RBI.repl r) ≡⟨ proj1 (red-children-eq1 (sym eq) repl-red (RBI.replrb r)) ⟩
+                black-depth rp-left ≡⟨ sym ( ⊔-idem _ ) ⟩
+                black-depth  rp-left ⊔ black-depth rp-left ≡⟨ cong (λ k → k ⊔ black-depth rp-left ) (sym rb18) ⟩
+                black-depth (PG.uncle pg) ⊔ black-depth rp-left ∎ )
+                  where open ≡-Reasoning
+            rb29 : color n1 ≡ Black
+            rb29 = proj2 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) x rb09) (sym (cong proj1 rb13)) )
+            rb30 : color rp-left ≡ Black
+            rb30 = proj1 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) (sym eq) (RBI.replrb r)) (cong proj1 rb23))
+            rb32 : suc (black-depth (PG.uncle pg)) ≡ black-depth (PG.grand pg)
+            rb32 = sym (proj1 ( black-children-eq1 x₁ rb33 rb02 ))
+            rb10 : RBtreeInvariant (node rkey ⟪ Black , proj2 vr ⟫ (node kg ⟪ Red , proj2 vg ⟫ (PG.uncle pg) rp-left ) (node kp vp rp-right n1) )
+            rb10 = rb-black _ _ rb19 (rb-red _ _ uncle-black rb30 rb18 rb05 rb26 ) (rbi-from-red-black _ _ _ _ rb28 rb06 rb27 rb20 rb16 rb13 )
+            rb17 : suc (black-depth (PG.uncle pg) ⊔ black-depth rp-left ⊔ black-depth (node kp vp rp-right n1)) ≡ black-depth (PG.grand pg)
+            rb17 = begin
+                 suc (black-depth (PG.uncle pg) ⊔ black-depth rp-left ⊔ black-depth (node kp vp rp-right n1)) ≡⟨ cong (λ k → suc (_ ⊔ k)) (sym rb19) ⟩
+                 suc (black-depth (PG.uncle pg) ⊔ black-depth rp-left ⊔ (black-depth (PG.uncle pg) ⊔ black-depth rp-left)) ≡⟨ cong suc ( ⊔-idem _) ⟩
+                 suc (black-depth (PG.uncle pg) ⊔ black-depth rp-left ) ≡⟨ cong (λ k → suc (_ ⊔ k)) (sym rb18) ⟩
+                 suc (black-depth (PG.uncle pg) ⊔ black-depth (PG.uncle pg)) ≡⟨ cong suc (⊔-idem _) ⟩
+                 suc (black-depth (PG.uncle pg))  ≡⟨ rb32 ⟩
+                 black-depth (PG.grand pg) ∎
+                    where open ≡-Reasoning
+        ... | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase52 where
+          insertCase52 : t
+          insertCase52 = next (PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.grand pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = rb02
+            ; replrb = subst (λ k → RBtreeInvariant k) rb10 (rb-black _ _ rb18 (rb-red _ _ uncle-black rb16 rb19 rb05 rb06) (RBI.replrb r) )
+            ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+            ; state = rebuild rb33 rb17 (subst (λ k → ¬ (k ≡ leaf)) (sym x₁) (λ ())) 
+           } rb15 where
+                -- outer case, repl  is not decomposed
+                -- lt          : kp < key
+                -- x           : PG.parent pg ≡ node kp vp n1 (RBI.tree r)
+                -- x₁          : PG.grand pg ≡ node kg vg (PG.uncle pg) (PG.parent pg)
+            rb01 : bt (Color ∧ A)
+            rb01 = to-black (node kp vp  (to-red (node kg vg (PG.uncle pg) n1) )(node rkey vr rp-left rp-right))
+            rb04 : kp < key
+            rb04 = lt
+            rb16 : color n1 ≡ Black
+            rb16 = proj1 (RBtreeChildrenColorBlack _ _ (subst (λ k → RBtreeInvariant k) x rb09) (trans (cong color (sym x)) pcolor))
+            rb13 : ⟪ Red , proj2 vp ⟫ ≡ vp
+            rb13 with subst (λ k → color k ≡ Red ) x pcolor
+            ... | refl = refl
+            rb14 : ⟪ Black , proj2 vg ⟫ ≡ vg
+            rb14 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02) (case2 pcolor)
+            ... | refl = refl
+            rb33 : color (PG.grand pg) ≡ Black
+            rb33 = subst (λ k → color k ≡ Black ) (sym x₁) (sym (cong proj1 rb14))
+            rb10 : node kp ⟪ Black , proj2 vp ⟫ (node kg ⟪ Red , proj2 vg ⟫ (PG.uncle pg) n1 ) repl ≡ rb01
+            rb10 = cong (λ  k → node _ _  _ k ) (sym eq)
+            rb12 : node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r)) ≡ PG.grand pg
+            rb12 = begin
+                 node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r))
+                       ≡⟨ cong₂ (λ j k → node kg j (PG.uncle pg) (node kp k n1 (RBI.tree r) ) ) rb14 rb13 ⟩
+                 node kg vg (PG.uncle pg) _ ≡⟨ cong (λ k → node _ _ _ k) (sym x) ⟩
+                 node kg vg (PG.uncle pg) (PG.parent pg) ≡⟨ sym x₁ ⟩
+                 PG.grand pg ∎ where open ≡-Reasoning
+            rb05 : RBtreeInvariant (PG.uncle pg)
+            rb05 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb02)
+            rb06 : RBtreeInvariant n1
+            rb06 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x rb09)
+            rb19 : black-depth (PG.uncle pg) ≡ black-depth n1
+            rb19 = sym (trans (sym ( proj1 (red-children-eq x (sym (cong proj1 rb13))  rb09) )) (sym (RBtreeEQ (subst (λ k → RBtreeInvariant k) x₁ rb02))))
+            rb18 : black-depth (PG.uncle pg) ⊔ black-depth n1 ≡ black-depth repl
+            rb18 = ?
+            rb17 : suc (black-depth (PG.uncle pg) ⊔ black-depth n1 ⊔ black-depth (node rkey vr rp-left rp-right)) ≡ black-depth (PG.grand pg)
+            rb17 = ?
+    replaceRBP1 : t
+    replaceRBP1 with RBI.state r
+    ... | rebuild ceq bdepth-eq ¬leaf = rebuildCase ceq bdepth-eq ¬leaf 
+    ... | top-black eq = exit stack (trans eq (cong (λ k → k ∷ []) rb00)) r where
+        rb00 : RBI.tree r ≡ orig
+        rb00 with si-property-last _ _ _ _ (subst (λ k → stackInvariant key (RBI.tree r) orig k) (eq) (RBI.si r))
+        ... | refl = refl
+    ... | rotate _ repl-red with stackToPG (RBI.tree r) orig stack (RBI.si r)
+    ... | case1 eq  = exit stack eq r     -- no stack, replace top node
+    ... | case2 (case1 eq) = insertCase4 orig refl eq (case1 repl-red) (RBI.si r)     -- one level stack, orig is parent of repl
+    ... | case2 (case2 pg) with color (PG.parent pg) in pcolor
+    ... | Black = insertCase1 where
+       -- Parent is Black, make color repl ≡ color tree then goto rebuildCase
+       rb00 : (pg : PG (Color ∧ A) key (RBI.tree r) stack) → stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+       rb00 pg = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+       treerb : (pg : PG (Color ∧ A) key (RBI.tree r) stack) → RBtreeInvariant (PG.parent pg)
+       treerb pg = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (rb00 pg))
+       rb08 : (pg : PG (Color ∧ A) key (RBI.tree r) stack) → treeInvariant (PG.parent pg)
+       rb08 pg = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ (rb00 pg))
+       insertCase1 : t
+       insertCase1 with PG.pg pg
+       ... | s2-s1p2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.parent pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = treerb pg
+            ; replrb = rb06
+            ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+            ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
+           } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+            rb01 : bt (Color ∧ A)
+            rb01 = node kp vp repl n1
+            rb03 : key < kp
+            rb03 = lt
+            rb04 :  ⟪ Black , proj2 vp ⟫ ≡ vp
+            rb04 with subst (λ k → color k ≡ Black) x pcolor
+            ... | refl = refl
+            rb07 : black-depth repl ≡ black-depth n1
+            rb07 = ?
+            rb05 : proj1 vp ≡ Black → black-depth rb01 ≡ black-depth (PG.parent pg)
+            rb05 refl = ?
+            rb06 : RBtreeInvariant rb01
+            rb06 = subst (λ k → RBtreeInvariant (node kp k repl n1))  rb04
+               ( rb-black _ _ rb07 (RBI.replrb r) (RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))))
+       ... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.parent pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = treerb pg
+            ; replrb = rb06
+            ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+            ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
+                
+           } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+               --- x  : PG.parent pg ≡ node kp vp n1 (RBI.tree r)
+               --- x₁ : PG.grand pg ≡ node kg vg (PG.parent pg) (PG.uncle pg)
+            rb01 : bt (Color ∧ A)
+            rb01 = node kp vp n1 repl
+            rb03 : kp < key
+            rb03 = lt
+            rb04 :  ⟪ Black , proj2 vp ⟫ ≡ vp
+            rb04 with subst (λ k → color k ≡ Black) x pcolor
+            ... | refl = refl
+            rb07 : black-depth repl ≡ black-depth n1
+            rb07 = ?
+            rb05 : proj1 vp ≡ Black → black-depth rb01 ≡ black-depth (PG.parent pg)
+            rb05 refl = ?
+            rb06 : RBtreeInvariant rb01
+            rb06 = subst (λ k → RBtreeInvariant (node kp k n1 repl ))  rb04
+               ( rb-black _ _ (sym rb07) (RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))) (RBI.replrb r) )
+       insertCase1 | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.parent pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = treerb pg
+            ; replrb = rb06
+            ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+            ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
+           } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+            rb01 : bt (Color ∧ A)
+            rb01 = node kp vp repl n1
+            rb03 : key < kp
+            rb03 = lt
+            rb04 :  ⟪ Black , proj2 vp ⟫ ≡ vp
+            rb04 with subst (λ k → color k ≡ Black) x pcolor
+            ... | refl = refl
+            rb07 : black-depth repl ≡ black-depth n1
+            rb07 = ?
+            rb05 : proj1 vp ≡ Black → black-depth rb01 ≡ black-depth (PG.parent pg)
+            rb05 refl = ?
+            rb06 : RBtreeInvariant rb01
+            rb06 = subst (λ k → RBtreeInvariant (node kp k repl n1))  rb04
+               ( rb-black _ _ rb07 (RBI.replrb r) (RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))))
+       insertCase1 | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = next (PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) record {
+            tree = PG.parent pg
+            ; repl = rb01
+            ; origti = RBI.origti r
+            ; origrb = RBI.origrb r
+            ; treerb = treerb pg
+            ; replrb = rb06
+            ; si = popStackInvariant _ _ _ _ _ (rb00 pg)
+            ; state = rebuild (cong color x)  (rb05 (trans (sym (cong color x)) pcolor)) (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ()))
+           } (subst₂ (λ j k → j < length k ) refl (sym (PG.stack=gp pg)) ≤-refl) where
+                -- x   : PG.parent pg ≡ node kp vp (RBI.tree r) n1
+                -- x₁  : PG.grand pg ≡ node kg vg (PG.uncle pg) (PG.parent pg)
+            rb01 : bt (Color ∧ A)
+            rb01 = node kp vp n1 repl
+            rb03 : kp < key
+            rb03 = lt
+            rb04 :  ⟪ Black , proj2 vp ⟫ ≡ vp
+            rb04 with subst (λ k → color k ≡ Black) x pcolor
+            ... | refl = refl
+            rb07 : black-depth repl ≡ black-depth n1
+            rb07 = ?
+            rb05 : proj1 vp ≡ Black → black-depth rb01 ≡ black-depth (PG.parent pg)
+            rb05 refl = ?
+            rb06 : RBtreeInvariant rb01
+            rb06 = subst (λ k → RBtreeInvariant (node kp k n1 repl ))  rb04
+               ( rb-black _ _ (sym rb07) (RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x (treerb pg))) (RBI.replrb r) )
+    ... | Red with PG.uncle pg in uneq
+    ... | leaf = insertCase5 repl refl pg repl-red (cong color uneq) pcolor
+    ... | node key₁ ⟪ Black , value₁ ⟫ t₁ t₂ = insertCase5 repl refl pg repl-red (cong color uneq) pcolor
+    ... | node key₁ ⟪ Red , value₁ ⟫ t₁ t₂ with PG.pg pg   -- insertCase2 : uncle and parent are Red, flip color and go up by two level
+    ... | s2-s1p2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
+        insertCase2 : t
+        insertCase2 = next  (PG.grand pg ∷ (PG.rest pg))
+            record {
+                 tree = PG.grand pg
+                 ; repl = to-red (node kg vg (to-black (node kp vp repl n1)) (to-black (PG.uncle pg)))
+                 ; origti = RBI.origti r
+                 ; origrb = RBI.origrb r
+                 ; treerb = rb01
+                 ; replrb = rb-red _ _ refl (RBtreeToBlackColor _ rb02) rb12 (rb-black _ _ rb13 (RBI.replrb r) rb04) (RBtreeToBlack _ rb02)
+                 ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+                 ; state = rotate _ refl 
+             }  rb15 where
+               rb00 : stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+               rb00 = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+               rb01 :  RBtreeInvariant (PG.grand pg)
+               rb01 = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))
+               rb02 : RBtreeInvariant (PG.uncle pg)
+               rb02 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb03 : RBtreeInvariant (PG.parent pg)
+               rb03 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb04 : RBtreeInvariant n1
+               rb04 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x rb03)
+               rb05 : { tree : bt (Color ∧ A) } → tree ≡ PG.uncle pg → tree ≡ node key₁ ⟪ Red , value₁ ⟫ t₁ t₂ → color (PG.uncle pg) ≡ Red
+               rb05 refl refl = refl
+               rb08 : treeInvariant (PG.parent pg)
+               rb08 = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00)
+               rb07 : treeInvariant (node kp vp (RBI.tree r) n1)
+               rb07 = subst (λ k → treeInvariant k) x (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00))
+               rb06 : key < kp
+               rb06 = lt
+               rb10 : vg ≡ ⟪ Black , proj2 vg ⟫
+               rb10 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01) (case1 pcolor)
+               ... | refl = refl
+               rb11 : vp ≡ ⟪ Red , proj2 vp ⟫
+               rb11 with subst (λ k → color k ≡ Red) x pcolor
+               ... | refl = refl
+               rb09 : PG.grand pg ≡ node kg ⟪ Black , proj2 vg ⟫ (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) (PG.uncle pg)
+               rb09 = begin
+                   PG.grand pg ≡⟨ x₁ ⟩
+                   node kg vg (PG.parent pg) (PG.uncle pg) ≡⟨ cong (λ k → node kg vg k (PG.uncle pg)) x ⟩
+                   node kg vg (node kp vp (RBI.tree r) n1) (PG.uncle pg) ≡⟨ cong₂ (λ j k → node kg j (node kp k (RBI.tree r) n1) (PG.uncle pg)) rb10 rb11  ⟩
+                   node kg ⟪ Black , proj2 vg ⟫ (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) (PG.uncle pg) ∎
+                     where open ≡-Reasoning
+               rb13 : black-depth repl ≡ black-depth n1
+               rb13 = ?
+               rb12 : suc (black-depth repl ⊔ black-depth n1) ≡ black-depth (to-black (PG.uncle pg))
+               rb12 = ?
+               rb15 : suc (length (PG.rest pg)) < length stack
+               rb15 = begin
+                  suc (suc (length (PG.rest pg))) ≤⟨ <-trans (n<1+n _) (n<1+n _) ⟩
+                  length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
+                  length stack ∎
+                     where open ≤-Reasoning
+    ... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
+        insertCase2 : t
+        insertCase2 = next  (PG.grand pg ∷ (PG.rest pg))
+            record {
+                 tree = PG.grand pg
+                 ; repl = to-red (node kg vg (to-black (node kp vp n1 repl)) (to-black (PG.uncle pg))  )
+                 ; origti = RBI.origti r
+                 ; origrb = RBI.origrb r
+                 ; treerb = rb01
+                 ; replrb = rb-red _ _ refl (RBtreeToBlackColor _ rb02) rb12 (rb-black _ _ (sym rb13) rb04 (RBI.replrb r)) (RBtreeToBlack _ rb02)
+                  ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+                 ; state = rotate _ refl 
+             }  rb15 where
+               --
+               -- lt       : kp < key
+               --  x       : PG.parent pg ≡ node kp vp n1 (RBI.tree r)
+               --- x₁      : PG.grand pg ≡ node kg vg (PG.parent pg) (PG.uncle pg)
+               --
+               rb00 : stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+               rb00 = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+               rb01 : RBtreeInvariant (PG.grand pg)
+               rb01 = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))
+               rb02 : RBtreeInvariant (PG.uncle pg)
+               rb02 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb03 : RBtreeInvariant (PG.parent pg)
+               rb03 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb04 : RBtreeInvariant n1
+               rb04 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x rb03)
+               rb05 : { tree : bt (Color ∧ A) } → tree ≡ PG.uncle pg → tree ≡ node key₁ ⟪ Red , value₁ ⟫ t₁ t₂ → color (PG.uncle pg) ≡ Red
+               rb05 refl refl = refl
+               rb08 : treeInvariant (PG.parent pg)
+               rb08 = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00)
+               rb07 : treeInvariant (node kp vp n1 (RBI.tree r) )
+               rb07 = subst (λ k → treeInvariant k) x (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00))
+               rb06 : kp < key
+               rb06 = lt
+               rb21 : key < kg   -- this can be a part of ParentGand relation
+               rb21 = si-property-< (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → treeInvariant k ) x₁ (siToTreeinvariant _ _ _ _ (RBI.origti r)
+                     (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))))
+                     (subst (λ k → stackInvariant key _ orig (PG.parent pg ∷ k ∷ PG.rest pg)) x₁ (popStackInvariant _ _ _ _ _ rb00))
+               rb10 : vg ≡ ⟪ Black , proj2 vg ⟫
+               rb10 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01) (case1 pcolor)
+               ... | refl = refl
+               rb11 : vp ≡ ⟪ Red , proj2 vp ⟫
+               rb11 with subst (λ k → color k ≡ Red) x pcolor
+               ... | refl = refl
+               rb09 : node kg ⟪ Black , proj2 vg ⟫  (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r) ) (PG.uncle pg) ≡ PG.grand pg
+               rb09 = sym ( begin
+                   PG.grand pg ≡⟨ x₁ ⟩
+                   node kg vg  (PG.parent pg) (PG.uncle pg) ≡⟨ cong (λ k → node kg vg k (PG.uncle pg)) x ⟩
+                   node kg vg  (node kp vp n1 (RBI.tree r) ) (PG.uncle pg)  ≡⟨ cong₂ (λ j k → node kg j  (node kp k n1 (RBI.tree r) ) (PG.uncle pg) ) rb10 rb11  ⟩
+                   node kg ⟪ Black , proj2 vg ⟫ (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r) ) (PG.uncle pg) ∎ )
+                     where open ≡-Reasoning
+               rb13 : black-depth repl ≡ black-depth n1
+               rb13 = ?
+               rb12 : suc (black-depth n1 ⊔ black-depth repl) ≡ black-depth (to-black (PG.uncle pg))
+               rb12 = ?
+               rb15 : suc (length (PG.rest pg)) < length stack
+               rb15 = begin
+                  suc (suc (length (PG.rest pg))) ≤⟨ <-trans (n<1+n _) (n<1+n _) ⟩
+                  length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
+                  length stack ∎
+                     where open ≤-Reasoning
+    ... | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
+        insertCase2 : t
+        insertCase2 = next  (PG.grand pg ∷ (PG.rest pg))
+            record {
+                 tree = PG.grand pg
+                 ; repl = to-red (node kg vg (to-black (PG.uncle pg)) (to-black (node kp vp repl n1)) )
+                 ; origti = RBI.origti r
+                 ; origrb = RBI.origrb r
+                 ; treerb = rb01
+                 ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+                 ; replrb = rb-red _ _ (RBtreeToBlackColor _ rb02) refl rb12 (RBtreeToBlack _ rb02) (rb-black _ _ rb13 (RBI.replrb r) rb04)
+                 ; state = rotate _ refl 
+             }  rb15 where
+                 -- x   : PG.parent pg ≡ node kp vp (RBI.tree r) n1
+                 -- x₁  : PG.grand pg ≡ node kg vg (PG.uncle pg) (PG.parent pg)
+               rb00 : stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+               rb00 = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+               rb01 :  RBtreeInvariant (PG.grand pg)
+               rb01 = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))
+               rb02 : RBtreeInvariant (PG.uncle pg)
+               rb02 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb03 : RBtreeInvariant (PG.parent pg)
+               rb03 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb04 : RBtreeInvariant n1
+               rb04 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x rb03)
+               rb05 : { tree : bt (Color ∧ A) } → tree ≡ PG.uncle pg → tree ≡ node key₁ ⟪ Red , value₁ ⟫ t₁ t₂ → color (PG.uncle pg) ≡ Red
+               rb05 refl refl = refl
+               rb08 : treeInvariant (PG.parent pg)
+               rb08 = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00)
+               rb07 : treeInvariant (node kp vp (RBI.tree r) n1)
+               rb07 = subst (λ k → treeInvariant k) x (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00))
+               rb06 : key < kp
+               rb06 = lt
+               rb21 : kg < key   -- this can be a part of ParentGand relation
+               rb21 = si-property-> (subst (λ k → ¬ (k ≡ leaf)) (sym x) (λ ())) (subst (λ k → treeInvariant k ) x₁ (siToTreeinvariant _ _ _ _ (RBI.origti r)
+                     (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))))
+                     (subst (λ k → stackInvariant key _ orig (PG.parent pg ∷ k ∷ PG.rest pg)) x₁ (popStackInvariant _ _ _ _ _ rb00))
+               rb10 : vg ≡ ⟪ Black , proj2 vg ⟫
+               rb10 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01) (case2 pcolor)
+               ... | refl = refl
+               rb11 : vp ≡ ⟪ Red , proj2 vp ⟫
+               rb11 with subst (λ k → color k ≡ Red) x pcolor
+               ... | refl = refl
+               rb09 : node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) ≡ PG.grand pg
+               rb09 = sym ( begin
+                   PG.grand pg ≡⟨ x₁ ⟩
+                   node kg vg (PG.uncle pg) (PG.parent pg)  ≡⟨ cong (λ k → node kg vg (PG.uncle pg) k) x ⟩
+                   node kg vg (PG.uncle pg) (node kp vp (RBI.tree r) n1)  ≡⟨ cong₂ (λ j k → node kg j (PG.uncle pg) (node kp k (RBI.tree r) n1) ) rb10 rb11  ⟩
+                   node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ (RBI.tree r) n1) ∎ )
+                     where open ≡-Reasoning
+               rb13 : black-depth repl ≡ black-depth n1
+               rb13 = ?
+               rb12 : black-depth (to-black (PG.uncle pg)) ≡ suc (black-depth repl ⊔ black-depth n1)
+               rb12 = ?
+               rb17 : suc (black-depth repl ⊔ black-depth n1) ⊔ black-depth (to-black (PG.uncle pg)) ≡ black-depth (PG.grand pg)
+               rb17 = begin
+                  suc (black-depth repl ⊔ black-depth n1) ⊔ black-depth (to-black (PG.uncle pg)) ≡⟨ cong (λ k → k ⊔ black-depth (to-black (PG.uncle pg))) (sym rb12) ⟩
+                  black-depth (to-black (PG.uncle pg)) ⊔ black-depth (to-black (PG.uncle pg)) ≡⟨ ⊔-idem _ ⟩
+                  black-depth (to-black (PG.uncle pg)) ≡⟨ sym (to-black-eq (PG.uncle pg) (cong color uneq )) ⟩
+                  suc (black-depth (PG.uncle pg)) ≡⟨ sym ( proj1 (black-children-eq x₁ (cong proj1 rb10) rb01 )) ⟩
+                  black-depth (PG.grand pg) ∎
+                     where open ≡-Reasoning
+               rb15 : suc (length (PG.rest pg)) < length stack
+               rb15 = begin
+                  suc (suc (length (PG.rest pg))) ≤⟨ <-trans (n<1+n _) (n<1+n _) ⟩
+                  length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
+                  length stack ∎
+                     where open ≤-Reasoning
+    ... | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} lt x x₁ = insertCase2 where
+           --- lt : kp < key
+           --- x  : PG.parent pg ≡ node kp vp n1 (RBI.tree r)
+           --- x₁ : PG.grand pg ≡ node kg vg (PG.uncle pg) (PG.parent pg)
+        insertCase2 : t
+        insertCase2 = next  (PG.grand pg ∷ (PG.rest pg))
+            record {
+                 tree = PG.grand pg
+                 ; repl = to-red (node kg vg (to-black (PG.uncle pg)) (to-black (node kp vp n1 repl )) )
+                 ; origti = RBI.origti r
+                 ; origrb = RBI.origrb r
+                 ; treerb = rb01
+                 ; replrb = rb-red _ _ (RBtreeToBlackColor _ rb02) refl rb12  (RBtreeToBlack _ rb02) (rb-black _ _ (sym rb13) rb04 (RBI.replrb r) )
+                 ; si = popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00)
+                 ; state = rotate _ refl 
+             }  rb15 where
+               rb00 : stackInvariant key (RBI.tree r) orig (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg)
+               rb00 = subst (λ k → stackInvariant key (RBI.tree r) orig k) (PG.stack=gp pg) (RBI.si r)
+               rb01 :  RBtreeInvariant (PG.grand pg)
+               rb01 = PGtoRBinvariant1 _ orig (RBI.origrb r) _ (popStackInvariant _ _ _ _ _ (popStackInvariant _ _ _ _ _ rb00))
+               rb02 : RBtreeInvariant (PG.uncle pg)
+               rb02 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb03 : RBtreeInvariant (PG.parent pg)
+               rb03 = RBtreeRightDown _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01)
+               rb04 : RBtreeInvariant n1
+               rb04 = RBtreeLeftDown _ _ (subst (λ k → RBtreeInvariant k) x rb03)
+               rb05 : { tree : bt (Color ∧ A) } → tree ≡ PG.uncle pg → tree ≡ node key₁ ⟪ Red , value₁ ⟫ t₁ t₂ → color (PG.uncle pg) ≡ Red
+               rb05 refl refl = refl
+               rb08 : treeInvariant (PG.parent pg)
+               rb08 = siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00)
+               rb07 : treeInvariant (node kp vp n1 (RBI.tree r) )
+               rb07 = subst (λ k → treeInvariant k) x (siToTreeinvariant _ _ _ _ (RBI.origti r) (popStackInvariant _ _ _ _ _ rb00))
+               rb06 : kp < key
+               rb06 = lt
+               rb10 : vg ≡ ⟪ Black , proj2 vg ⟫
+               rb10 with RBtreeParentColorBlack _ _ (subst (λ k → RBtreeInvariant k) x₁ rb01) (case2 pcolor)
+               ... | refl = refl
+               rb11 : vp ≡ ⟪ Red , proj2 vp ⟫
+               rb11 with subst (λ k → color k ≡ Red) x pcolor
+               ... | refl = refl
+               rb09 : PG.grand pg ≡ node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r) )
+               rb09 = begin
+                   PG.grand pg ≡⟨ x₁ ⟩
+                   node kg vg (PG.uncle pg) (PG.parent pg) ≡⟨ cong (λ k → node kg vg (PG.uncle pg) k) x ⟩
+                   node kg vg (PG.uncle pg) (node kp vp n1 (RBI.tree r) )  ≡⟨ cong₂ (λ j k → node kg j (PG.uncle pg) (node kp k n1 (RBI.tree r) ) ) rb10 rb11  ⟩
+                   node kg ⟪ Black , proj2 vg ⟫ (PG.uncle pg) (node kp ⟪ Red , proj2 vp ⟫ n1 (RBI.tree r) )  ∎
+                     where open ≡-Reasoning
+               rb13 : black-depth repl ≡ black-depth n1
+               rb13 = ? 
+               rb12 : black-depth (to-black (PG.uncle pg)) ≡ suc (black-depth n1 ⊔ black-depth repl)
+               rb12 = ?
+               rb15 : suc (length (PG.rest pg)) < length stack
+               rb15 = begin
+                  suc (suc (length (PG.rest pg))) ≤⟨ <-trans (n<1+n _) (n<1+n _) ⟩
+                  length (RBI.tree r ∷ PG.parent pg ∷ PG.grand pg ∷ PG.rest pg) ≡⟨ cong length (sym (PG.stack=gp pg)) ⟩
+                  length stack ∎
+                     where open ≤-Reasoning
+
+
+insertRBTreeP : {n m : Level} {A : Set n} {t : Set m} → (tree : bt (Color ∧ A)) → (key : ℕ) → (value : A)
+   → treeInvariant tree → RBtreeInvariant tree
+   → (exit : (stack  : List (bt (Color ∧ A))) → stack ≡ (tree ∷ []) → RBI key value tree stack → t ) → t
+insertRBTreeP {n} {m} {A} {t} orig key value ti rbi exit = TerminatingLoopS (bt (Color ∧ A) ∧ List (bt (Color ∧ A)))
+ {λ p → RBtreeInvariant (proj1 p) ∧ stackInvariant key (proj1 p) orig (proj2 p) } (λ p → bt-depth (proj1 p)) ⟪ orig , orig ∷ [] ⟫ ⟪ rbi , s-nil ⟫
+       $ λ p RBP findLoop → findRBT key (proj1 p) orig (proj2 p) RBP  (λ t1 s1 P2 lt1 → findLoop ⟪ t1 ,  s1  ⟫ P2 lt1 )
+       $ λ tr1 st P2 O → createRBT key value orig rbi ti tr1 st (proj2 P2) O
+       $ λ st rbi → TerminatingLoopS (List (bt (Color ∧ A))) {λ stack → RBI key value orig stack }
+          (λ stack  → length stack ) st rbi
+            $ λ stack rbi replaceLoop → replaceRBP key value orig stack rbi (λ stack1 rbi1 lt → replaceLoop stack1 rbi1 lt )
+            $ λ stack eq r → exit stack eq r
+
--- a/logic.agda	Tue Jul 09 08:51:13 2024 +0900
+++ b/logic.agda	Sat Jul 20 17:01:50 2024 +0900
@@ -1,3 +1,4 @@
+{-# OPTIONS --safe --cubical-compatible #-}
 module logic where
 
 open import Level