view hoareBinaryTree1.agda @ 898:e5ac221866c5

...
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Wed, 29 May 2024 21:31:02 +0900
parents f09d59c856a1
children 58954abea83e
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module hoareBinaryTree1 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 )

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)

data replacedTree  {n : Level} {A : Set n} (key : ℕ) (value : A)  : (before after : bt A ) → Set n where
    r-leaf : replacedTree key value leaf (node key value leaf leaf)
    r-node : {value₁ : A} → {t t₁ : bt A} → replacedTree key value (node key value₁ t t₁) (node key value t t₁)
    r-right : {k : ℕ } {v1 : A} → {t t1 t2 : bt A}
          → k < key →  replacedTree key value t2 t →  replacedTree key value (node k v1 t1 t2) (node k v1 t1 t)
    r-left : {k : ℕ } {v1 : A} → {t t1 t2 : bt A}
          → key < k →  replacedTree key value t1 t →  replacedTree key value (node k v1 t1 t2) (node k v1 t t2)

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 key₁ kp : ℕ} {value₁ value₂ : A} {tree orig tree₁ tree₂ tree₃ : bt A} → {stack  : List (bt A)}
   → tree ≡ node key₁ value₁ tree₁ tree₂
   → treeInvariant (node kp value₂ tree  tree₃ )
   → stackInvariant key tree orig (tree ∷ node kp value₂ tree  tree₃ ∷ stack)
   → key < kp
si-property-< refl (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-right .(node _ _ _ _) _ .(node _ _ _ _) x s-nil) = ⊥-elim (nat-<> x₁ x₂)
si-property-< refl (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-< refl (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-< refl (t-left _ _ x₁ x₂ x₃ ti) (s-left .(node _ _ _ _) _ .leaf x s-nil) = x
si-property-< refl (t-node _ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-left .(node _ _ _ _) _ .(node key₂ _ _ _) x s-nil) = x
si-property-< refl ti (s-left .(node _ _ _ _) _ tree x (s-right .(node _ _ (node _ _ _ _) tree) _ tree₁ x₁ si)) = x
si-property-< refl ti (s-left .(node _ _ _ _) _ tree x (s-left .(node _ _ (node _ _ _ _) tree) _ tree₁ x₁ si)) = x

si-property-> :  {n : Level} {A : Set n} {key key₁ kp : ℕ} {value₁ value₂ : A} {tree orig tree₁ tree₂ tree₃ : bt A} → {stack  : List (bt A)}
   → tree ≡ node key₁ value₁ tree₁ tree₂
   → treeInvariant (node kp value₂ tree₃  tree )
   → stackInvariant key tree orig (tree ∷ node kp value₂ tree₃  tree ∷ stack)
   → kp < key
si-property-> refl ti (s-right .(node _ _ _ _) _ tree₁ x s-nil) = x
si-property-> refl ti (s-right .(node _ _ _ _) _ tree₁ x (s-right .(node _ _ tree₁ (node _ _ _ _)) _ tree₂ x₁ si)) = x
si-property-> refl ti (s-right .(node _ _ _ _) _ tree₁ x (s-left .(node _ _ tree₁ (node _ _ _ _)) _ tree x₁ si)) = x
si-property-> refl (t-node _ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (s-left .(node _ _ _ _) _ .(node _ _ _ _) x s-nil) = ⊥-elim (nat-<> x₁ x₂)
si-property-> refl (t-node _ _ _ x₂ x₃ x₄ x₅ x₆ x₇ ti ti₁) (s-left .(node _ _ _ _) _ .(node _ _ _ _) x (s-right .(node _ _ (node _ _ _ _) (node _ _ _ _)) _ tree₁ x₁ si)) = ⊥-elim (nat-<> x₂ x₃)
si-property-> refl (t-node _ _ _ x₂ x₃ x₄ x₅ x₆ x₇ ti ti₁) (s-left .(node _ _ _ _) _ .(node _ _ _ _) x (s-left .(node _ _ (node _ _ _ _) (node _ _ _ _)) _ tree x₁ si)) = ⊥-elim (nat-<> x₂ x₃)

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


-- Diffkey : {n : Level} (A : Set n) (tree0 : bt A) → (key : ℕ) →  (tree : bt A) → (stack  : List (bt A)) → (si : stackInvariant key tree tree0 stack) → Set
-- Diffkey A leaf key .leaf .(leaf ∷ []) s-nil = ?
-- Diffkey A (node key₁ value tree0 tree1) key .(node key₁ value tree0 tree1) .(node key₁ value tree0 tree1 ∷ []) s-nil = ?
-- Diffkey A tree0 key leaf .(leaf ∷ _) (s-right .leaf .tree0 tree₁ x si) = ?
-- Diffkey A tree0 key (node key₁ value tree tree₂) .(node key₁ value tree tree₂ ∷ _) (s-right .(node key₁ value tree tree₂) .tree0 tree₁ x si) = ?
-- Diffkey A tree0 key tree .(tree ∷ _) (s-left .tree .tree0 tree₁ x si) = ?

-- si-property-ne :  {n : Level} {A : Set n}  (key : ℕ) (tree tree0 : bt A) → (stack  : List (bt A)) →  stackInvariant key tree tree0 stack
--    → length stack > 1 → ¬ ( node-key tree ≡ just key )
-- si-property-ne = ?

rt-property1 :  {n : Level} {A : Set n} (key : ℕ) (value : A) (tree tree1 : bt A ) → replacedTree key value tree tree1 → ¬ ( tree1 ≡ leaf )
rt-property1 {n} {A} key value .leaf .(node key value leaf leaf) r-leaf ()
rt-property1 {n} {A} key value .(node key _ _ _) .(node key value _ _) r-node ()
rt-property1 {n} {A} key value .(node _ _ _ _) _ (r-right x rt) = λ ()
rt-property1 {n} {A} key value .(node _ _ _ _) _ (r-left x rt) = λ ()

rt-property-leaf : {n : Level} {A : Set n} {key : ℕ} {value : A} {repl : bt A} → replacedTree key value leaf repl → repl ≡ node key value leaf leaf
rt-property-leaf r-leaf = refl

rt-property-¬leaf : {n : Level} {A : Set n} {key : ℕ} {value : A} {tree : bt A} → ¬ replacedTree key value tree leaf
rt-property-¬leaf ()

rt-property-key : {n : Level} {A : Set n} {key key₂ key₃ : ℕ} {value value₂ value₃ : A} {left left₁ right₂ right₃ : bt A}
    →  replacedTree key value (node key₂ value₂ left right₂) (node key₃ value₃ left₁ right₃) → key₂ ≡ key₃
rt-property-key r-node = refl
rt-property-key (r-right x ri) = refl
rt-property-key (r-left x ri) = refl


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

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

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)
     → replacedTree key value tree repl → key₁ < key → tr> key₁ tree → tr> key₁ repl
ri-tr> .leaf .(node key value leaf leaf) key key₁ value r-leaf a tgt = ⟪ a , ⟪ tt , tt ⟫ ⟫
ri-tr> .(node key _ _ _) .(node key value _ _) key key₁ value r-node a tgt = ⟪ a , ⟪ proj1 (proj2 tgt) , proj2 (proj2 tgt) ⟫ ⟫
ri-tr> .(node _ _ _ _) .(node _ _ _ _) key key₁ value (r-right x ri) a tgt = ⟪ proj1 tgt , ⟪ proj1 (proj2 tgt) , ri-tr> _ _ _ _ _ ri a (proj2 (proj2 tgt)) ⟫ ⟫
ri-tr> .(node _ _ _ _) .(node _ _ _ _) key key₁ value (r-left x ri) a tgt = ⟪ proj1 tgt , ⟪  ri-tr> _ _ _ _ _ ri a (proj1 (proj2 tgt)) , proj2 (proj2 tgt)  ⟫ ⟫

ri-tr<  : {n : Level} {A : Set n}  → (tree repl : bt A) → (key key₁ : ℕ) → (value : A)
     → replacedTree key value tree repl → key < key₁ → tr< key₁ tree → tr< key₁ repl
ri-tr< .leaf .(node key value leaf leaf) key key₁ value r-leaf a tgt = ⟪ a , ⟪ tt , tt ⟫ ⟫
ri-tr< .(node key _ _ _) .(node key value _ _) key key₁ value r-node a tgt = ⟪ a , ⟪ proj1 (proj2 tgt) , proj2 (proj2 tgt) ⟫ ⟫
ri-tr< .(node _ _ _ _) .(node _ _ _ _) key key₁ value (r-right x ri) a tgt = ⟪ proj1 tgt , ⟪ proj1 (proj2 tgt) , ri-tr< _ _ _ _ _ ri a (proj2 (proj2 tgt)) ⟫ ⟫
ri-tr< .(node _ _ _ _) .(node _ _ _ _) key key₁ value (r-left x ri) a tgt = ⟪ proj1 tgt , ⟪  ri-tr< _ _ _ _ _ ri a (proj1 (proj2 tgt)) , proj2 (proj2 tgt)  ⟫ ⟫

<-tr>  : {n : Level} {A : Set n}  → {tree : bt A} → {key₁ key₂ : ℕ} → tr> key₁ tree → key₂ < key₁  → tr> key₂ tree
<-tr> {n} {A} {leaf} {key₁} {key₂} tr lt = tt
<-tr> {n} {A} {node key value t t₁} {key₁} {key₂} tr lt = ⟪ <-trans lt (proj1 tr) , ⟪ <-tr> (proj1 (proj2 tr)) lt , <-tr> (proj2 (proj2 tr)) lt ⟫ ⟫

>-tr<  : {n : Level} {A : Set n}  → {tree : bt A} → {key₁ key₂ : ℕ} → tr< key₁ tree → key₁ < key₂  → tr< key₂ tree
>-tr<  {n} {A} {leaf} {key₁} {key₂} tr lt = tt
>-tr<  {n} {A} {node key value t t₁} {key₁} {key₂} tr lt = ⟪ <-trans (proj1 tr) lt , ⟪ >-tr< (proj1 (proj2 tr)) lt , >-tr< (proj2 (proj2 tr)) lt ⟫ ⟫

RTtoTI0  : {n : Level} {A : Set n}  → (tree repl : bt A) → (key : ℕ) → (value : A) → treeInvariant tree
     → replacedTree key value tree repl → treeInvariant repl
RTtoTI0 .leaf .(node key value leaf leaf) key value ti r-leaf = t-single key value
RTtoTI0 .(node key _ leaf leaf) .(node key value leaf leaf) key value (t-single .key _) r-node = t-single key value
RTtoTI0 .(node key _ leaf (node _ _ _ _)) .(node key value leaf (node _ _ _ _)) key value (t-right _ _ x a b ti) r-node = t-right _ _ x a b ti
RTtoTI0 .(node key _ (node _ _ _ _) leaf) .(node key value (node _ _ _ _) leaf) key value (t-left _ _ x a b ti) r-node = t-left _ _ x a b ti
RTtoTI0 .(node key _ (node _ _ _ _) (node _ _ _ _)) .(node key value (node _ _ _ _) (node _ _ _ _)) key value (t-node _ _ _ x x₁ a b c d ti ti₁) r-node = t-node _ _ _ x x₁ a b c d ti ti₁
-- r-right case
RTtoTI0 (node _ _ leaf leaf) (node _ _ leaf .(node key value leaf leaf)) key value (t-single _ _) (r-right x r-leaf) = t-right _ _ x _ _ (t-single key value)
RTtoTI0 (node _ _ leaf right@(node _ _ _ _)) (node key₁ value₁ leaf leaf) key value (t-right _ _ x₁ a b ti) (r-right x ri) = t-single key₁ value₁
RTtoTI0 (node key₁ _ leaf right@(node key₂ _ left₁ right₁)) (node key₁ value₁ leaf right₃@(node key₃ _ left₂ right₂)) key value (t-right key₄ key₅ x₁ a b ti) (r-right x ri) =
      t-right _ _ (subst (λ k → key₁ < k ) (rt-property-key ri) x₁) (rr00 ri a ) (rr02 ri b) (RTtoTI0 right right₃ key value ti ri) where
         rr00 : replacedTree key value (node key₂ _ left₁ right₁) (node key₃ _ left₂ right₂) → tr> key₁ left₁ → tr> key₁ left₂
         rr00 r-node tb = tb
         rr00 (r-right x ri) tb = tb
         rr00 (r-left x₂ ri) tb = ri-tr> _ _ _ _ _ ri x tb
         rr02 : replacedTree key value (node key₂ _ left₁ right₁) (node key₃ _ left₂ right₂) → tr> key₁ right₁ → tr> key₁ right₂
         rr02 r-node tb = tb
         rr02 (r-right x₂ ri) tb = ri-tr> _ _ _ _ _ ri x tb
         rr02 (r-left x ri) tb = tb
RTtoTI0 (node key₁ _ (node _ _ _ _) leaf) (node key₁ _ (node key₃ value left right) leaf) key value₁ (t-left _ _ x₁ a b ti) (r-right x ())
RTtoTI0 (node key₁ _ (node key₃ _ _ _) leaf) (node key₁ _ (node key₃ value₃ _ _) (node key value leaf leaf)) key value (t-left _ _ x₁ a b ti) (r-right x r-leaf) =
      t-node _ _ _ x₁ x a b tt tt ti (t-single key value)
RTtoTI0 (node key₁ _ (node _ _ left₀ right₀) (node key₂ _ left₁ right₁)) (node key₁ _ (node _ _ left₂ right₂) (node key₃ _ left₃ right₃)) key value (t-node _ _ _ x₁ x₂ a b c d ti ti₁) (r-right x ri) =
      t-node _ _ _ x₁ (subst (λ k → key₁ < k ) (rt-property-key ri) x₂) a b (rr00 ri c) (rr02 ri d) ti (RTtoTI0 _ _ key value ti₁ ri) where
         rr00 : replacedTree key value (node key₂ _ _ _) (node key₃ _ _ _) → tr> key₁ left₁ → tr> key₁ left₃
         rr00 r-node tb = tb
         rr00 (r-right x₃ ri) tb = tb
         rr00 (r-left x₃ ri) tb = ri-tr> _ _ _ _ _ ri x tb
         rr02 : replacedTree key value (node key₂ _ _ _) (node key₃ _ _ _) → tr> key₁ right₁ → tr> key₁ right₃
         rr02 r-node tb = tb
         rr02 (r-right x₃ ri) tb = ri-tr> _ _ _ _ _ ri x tb
         rr02 (r-left x₃ ri) tb = tb
-- r-left case
RTtoTI0 .(node _ _ leaf leaf) .(node _ _ (node key value leaf leaf) leaf) key value (t-single _ _) (r-left x r-leaf) = t-left _ _ x tt tt (t-single _ _ )
RTtoTI0 .(node _ _ leaf (node _ _ _ _)) (node key₁ value₁ (node key value leaf leaf) (node _ _ _ _)) key value (t-right _ _ x₁ a b ti) (r-left x r-leaf) =
      t-node _ _ _ x x₁ tt tt a b (t-single key value) ti
RTtoTI0 (node key₃ _ (node key₂ _ left₁ right₁) leaf) (node key₃ _ (node key₁ value₁ left₂ right₂) leaf) key value (t-left _ _ x₁ a b ti) (r-left x ri) =
      t-left _ _ (subst (λ k → k < key₃ ) (rt-property-key ri) x₁) (rr00 ri a) (rr02 ri b) (RTtoTI0 _ _ key value ti ri) where -- key₁ < key₃
         rr00 : replacedTree key value (node key₂ _ left₁ right₁) (node key₁ _ left₂ right₂) → tr< key₃ left₁ → tr< key₃ left₂
         rr00 r-node tb = tb
         rr00 (r-right x₂ ri) tb = tb
         rr00 (r-left x₂ ri) tb = ri-tr< _ _ _ _ _ ri x tb
         rr02 : replacedTree key value (node key₂ _ left₁ right₁) (node key₁ _ left₂ right₂) → tr< key₃ right₁ → tr< key₃ right₂
         rr02 r-node tb = tb
         rr02 (r-right x₃ ri) tb = ri-tr< _ _ _ _ _ ri x tb
         rr02 (r-left x₃ ri) tb = tb
RTtoTI0 (node key₁ _ (node key₂ _ left₂ right₂) (node key₃ _ left₃ right₃)) (node key₁ _ (node key₄ _ left₄ right₄) (node key₅ _ left₅ right₅)) key value (t-node _ _ _ x₁ x₂ a b c d ti ti₁) (r-left x ri) =
      t-node _ _ _ (subst (λ k → k < key₁ ) (rt-property-key ri) x₁) x₂  (rr00 ri a) (rr02 ri b) c d (RTtoTI0 _ _ key value ti ri) ti₁ where
         rr00 : replacedTree key value (node key₂ _ left₂ right₂) (node key₄ _ left₄ right₄) → tr< key₁ left₂ → tr< key₁ left₄
         rr00 r-node tb = tb
         rr00 (r-right x₃ ri) tb = tb
         rr00 (r-left x₃ ri) tb = ri-tr< _ _ _ _ _ ri x tb
         rr02 : replacedTree key value (node key₂ _ left₂ right₂) (node key₄ _ left₄ right₄) → tr< key₁ right₂ → tr< key₁ right₄
         rr02 r-node tb = tb
         rr02 (r-right x₃ ri) tb = ri-tr< _ _ _ _ _ ri x tb
         rr02 (r-left x₃ ri) tb = tb

-- RTtoTI1  : {n : Level} {A : Set n}  → (tree repl : bt A) → (key : ℕ) → (value : A) → treeInvariant repl
--      → replacedTree key value tree repl → treeInvariant tree
-- RTtoTI1 .leaf .(node key value leaf leaf) key value ti r-leaf = t-leaf
-- RTtoTI1 (node key value₁ leaf leaf) .(node key value leaf leaf) key value (t-single .key .value) r-node = t-single key value₁
-- RTtoTI1 .(node key _ leaf (node _ _ _ _)) .(node key value leaf (node _ _ _ _)) key value (t-right _ _ x a b ti) r-node = t-right _ _ x a b ti
-- RTtoTI1 .(node key _ (node _ _ _ _) leaf) .(node key value (node _ _ _ _) leaf) key value (t-left _ _ x a b ti) r-node = t-left _ _ x a b ti
-- RTtoTI1 .(node key _ (node _ _ _ _) (node _ _ _ _)) .(node key value (node _ _ _ _) (node _ _ _ _)) key value (t-node _ _ _ x x₁ a b c d ti ti₁) r-node = t-node _ _ _ x x₁ a b c d ti ti₁
-- -- r-right case
-- RTtoTI1 (node key₁ value₁ leaf leaf) (node key₁ _ leaf (node _ _ _ _)) key value (t-right _ _ x₁ a b ti) (r-right x r-leaf) = t-single key₁ value₁
-- RTtoTI1 (node key₁ value₁ leaf (node key₂ value₂ t2 t3)) (node key₁ _ leaf (node key₃ _ _ _)) key value (t-right _ _ x₁ a b ti) (r-right x ri) =
--    t-right _ _ (subst (λ k → key₁ < k ) (sym (rt-property-key ri)) x₁) ? ?  (RTtoTI1 _ _ key value ti ri) -- key₁ < key₂
-- RTtoTI1 (node _ _ (node _ _ _ _) leaf) (node _ _ (node _ _ _ _) (node key value _ _)) key value (t-node _ _ _ x₁ x₂ a b c d ti ti₁) (r-right x r-leaf) =
--     t-left _ _ x₁ ? ? ti
-- RTtoTI1 (node key₄ _ (node key₃ _ _ _) (node key₁ value₁ n n₁)) (node key₄ _ (node key₃ _ _ _) (node key₂ _ _ _)) key value (t-node _ _ _ x₁ x₂ a b c d ti ti₁) (r-right x ri) = t-node _ _ _ x₁ (subst (λ k → key₄ < k ) (sym (rt-property-key ri)) x₂) a b ? ? ti (RTtoTI1 _ _ key value ti₁ ri) -- key₄ < key₁
-- -- r-left case
-- RTtoTI1 (node key₁ value₁ leaf leaf) (node key₁ _ _ leaf) key value (t-left _ _ x₁ a b ti) (r-left x ri) = t-single key₁ value₁
-- RTtoTI1 (node key₁ _ (node key₂ value₁ n n₁) leaf) (node key₁ _ (node key₃ _ _ _) leaf) key value (t-left _ _ x₁ a b ti) (r-left x ri) =
--    t-left _ _ (subst (λ k → k < key₁ ) (sym (rt-property-key ri)) x₁) ? ? (RTtoTI1 _ _ key value ti ri) -- key₂ < key₁
-- RTtoTI1 (node key₁ value₁ leaf _) (node key₁ _ _ _) key value (t-node _ _ _ x₁ x₂ a b c d ti ti₁) (r-left x r-leaf) = t-right _ _ x₂ c d ti₁
-- 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

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 =
   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 ∷ [] ⟫  ⟪ P0 , 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 = P0 ; 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 ⟪ RTtoTI0 _ _ _ _ (proj1 P) (proj2 P) , proj2 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

-- 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 = 0
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

--
--  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

data replacedRBTree  {n : Level} {A : Set n} (key : ℕ) (value : A)  : (before after : bt (Color ∧ A) ) → Set n where
    -- no rotation case
    rbr-leaf : replacedRBTree key value leaf (node key ⟪ Red , value ⟫ leaf leaf)
    rbr-node : {value₁ : A} → {ca : Color } → {t t₁ : bt (Color ∧ A)}
          → replacedRBTree key value (node key ⟪ ca , value₁ ⟫ t t₁) (node key ⟪ ca , value ⟫ t t₁)
    rbr-right : {k : ℕ } {v1 : A} → {ca : Color} → {t t1 t2 : bt (Color ∧ A)}
          → color t2 ≡ color t
          → k < key →  replacedRBTree key value t2 t →  replacedRBTree key value (node k ⟪ ca , v1 ⟫ t1 t2) (node k ⟪ ca , v1 ⟫ t1 t)
    rbr-left  : {k : ℕ } {v1 : A} → {ca : Color} → {t t1 t2 : bt (Color ∧ A)}
          → color t1 ≡ color t
          → key < k →  replacedRBTree key value t1 t →  replacedRBTree key value (node k ⟪ ca , v1 ⟫ t1 t2) (node k ⟪ ca , v1 ⟫ t t2) -- k < key → key < k
    -- in all other case, color of replaced node is changed from Black to Red
    -- case1 parent is black
    rbr-black-right : {t t₁ t₂ : bt (Color ∧ A)} {value₁ : A} {key₁ : ℕ}
         → color t₂ ≡ Red → key₁ < key  → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node key₁ ⟪ Black , value₁ ⟫ t t₁) (node key₁ ⟪ Black , value₁ ⟫ t t₂)
    rbr-black-left : {t t₁ t₂ : bt (Color ∧ A)} {value₁ : A} {key₁ : ℕ}
         → color t₂ ≡ Red  → key < key₁ → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node key₁ ⟪ Black , value₁ ⟫ t₁ t) (node key₁ ⟪ Black , value₁ ⟫ t₂ t)

    -- case2 both parent and uncle are red (should we check uncle color?), flip color and up
    rbr-flip-ll : {t t₁ t₂ uncle : bt (Color ∧ A)} {kg kp : ℕ} {vg vp : A}
         → color t₂ ≡ Red → color uncle ≡ Red → key < kp  → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ (node kp ⟪ Red   , vp ⟫ t₁ t)           uncle)
                                    (node kg ⟪ Red ,   vg ⟫ (node kp ⟪ Black , vp ⟫ t₂ t) (to-black uncle))
    rbr-flip-lr : {t t₁ t₂ uncle : bt (Color ∧ A)} {kg kp : ℕ} {vg vp : A}
         → color t₂ ≡ Red → color uncle ≡ Red →  kp < key → key < kg   → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ (node kp ⟪ Red   , vp ⟫ t t₁)           uncle)
                                    (node kg ⟪ Red ,   vg ⟫ (node kp ⟪ Black , vp ⟫ t t₂) (to-black uncle))
    rbr-flip-rl : {t t₁ t₂ uncle : bt (Color ∧ A)} {kg kp : ℕ} {vg vp : A}
         → color t₂ ≡ Red → color uncle ≡ Red → kg < key → key < kp  → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ uncle            (node kp ⟪ Red   , vp ⟫ t₁ t))
                                    (node kg ⟪ Red ,   vg ⟫ (to-black uncle) (node kp ⟪ Black , vp ⟫ t₂ t))
    rbr-flip-rr : {t t₁ t₂ uncle : bt (Color ∧ A)} {kg kp : ℕ} {vg vp : A}
         → color t₂ ≡ Red → color uncle ≡ Red → kp < key   → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ uncle            (node kp ⟪ Red   , vp ⟫ t t₁))
                                    (node kg ⟪ Red ,   vg ⟫ (to-black uncle) (node kp ⟪ Black , vp ⟫ t t₂))

    -- case6 the node is outer, rotate grand
    rbr-rotate-ll : {t t₁ t₂ uncle : bt (Color ∧ A)} {kg kp : ℕ} {vg vp : A}
         → color t₂ ≡ Red → key < kp  → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ (node kp ⟪ Red , vp ⟫ t₁ t)    uncle)
                                    (node kp ⟪ Black , vp ⟫ t₂                             (node kg ⟪ Red , vg ⟫ t uncle))
    rbr-rotate-rr : {t t₁ t₂ uncle : bt (Color ∧ A)} {kg kp : ℕ} {vg vp : A}
         → color t₂ ≡ Red → kp < key → replacedRBTree key value t₁ t₂
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ uncle                          (node kp ⟪ Red   , vp ⟫ t t₁))
                                    (node kp ⟪ Black , vp ⟫ (node kg ⟪ Red , vg ⟫ uncle t) t₂ )
    -- case56 the node is inner, make it outer and rotate grand
    rbr-rotate-lr : {t t₁ uncle : bt (Color ∧ A)} (t₂ t₃ : bt (Color ∧ A)) (kg kp kn : ℕ) {vg vp vn : A}
         → color t₃ ≡ Red → kp < key → key < kg
         → replacedRBTree key value t₁ (node kn ⟪ Red , vn ⟫ t₂ t₃)
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ (node kp ⟪ Red , vp ⟫ t t₁)     uncle)
                                    (node kn ⟪ Black , vn ⟫ (node kp ⟪ Red , vp ⟫ t t₂)     (node kg ⟪ Red , vg ⟫ t₃ uncle))
    rbr-rotate-rl : {t t₁ uncle : bt (Color ∧ A)} (t₂ t₃ : bt (Color ∧ A)) (kg kp kn : ℕ) {vg vp vn : A}
         → color t₃ ≡ Red → kg < key → key < kp
         → replacedRBTree key value t₁ (node kn ⟪ Red , vn ⟫ t₂ t₃)
         → replacedRBTree key value (node kg ⟪ Black , vg ⟫ uncle                           (node kp ⟪ Red , vp ⟫ t₁ t))
                                    (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , vg ⟫ uncle t₂) (node kp ⟪ Red , vp ⟫ t₃ t))


--
-- Parent Grand Relation
--   should we require stack-invariant?
--

data ParentGrand {n : Level} {A : Set 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 }
        → parent ≡ node kp vp self n1 → grand ≡ node kg vg parent n2 → ParentGrand self parent n2 grand
    s2-1sp2 : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
        → parent ≡ node kp vp n1 self → grand ≡ node kg vg parent n2 → ParentGrand self parent n2 grand
    s2-s12p : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
        → parent ≡ node kp vp self n1 → grand ≡ node kg vg n2 parent → ParentGrand self parent n2 grand
    s2-1s2p : {kp kg : ℕ} {vp vg : A} → {n1 n2 : bt A} {parent grand : bt A }
        → parent ≡ node kp vp n1 self → grand ≡ node kg vg n2 parent → ParentGrand self parent n2 grand

record PG {n : Level } (A : Set n) (self : bt A) (stack : List (bt A)) : Set n where
    field
       parent grand uncle : bt A
       pg : ParentGrand 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))} → black-depth repl ≡ black-depth (child-replaced key tree)
       → (rotated : replacedRBTree key value tree repl)
       → RBI-state key value tree repl stack  -- one stage up
   rotate  : {tree repl : bt (Color ∧ A) } {stack : List (bt (Color ∧ A))} → color repl ≡ Red → black-depth repl ≡ black-depth (child-replaced key tree)
       → (rotated : replacedRBTree key value tree repl)
       → RBI-state key value tree repl stack  -- two stages up
   top-black : {tree repl : bt (Color ∧ A) } → {stack : List (bt (Color ∧ A))}  → stack ≡ tree ∷ []
       → (rotated : replacedRBTree key value (to-black tree) repl)
       → RBI-state key value tree repl stack

record RBI {n : Level} {A : Set n} (key : ℕ) (value : A) (orig repl : bt (Color ∧ A) ) (stack : List (bt (Color ∧ A)))  : Set n where
   field
       tree : 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) ()

⊔-succ : {m n : ℕ} → suc (m ⊔ n) ≡ suc m ⊔ suc n
⊔-succ {m} {n} = refl

RB-repl→eq  : {n : Level} {A : Set n}  → (tree repl : bt (Color ∧ A)) → {key : ℕ} → {value : A}
     → RBtreeInvariant tree
     → replacedRBTree key value tree repl → black-depth tree ≡ black-depth repl
RB-repl→eq = ?
--   RB-repl→eq {n} {A} .leaf .(node _ ⟪ Red , _ ⟫ leaf leaf) rbt rbr-leaf = refl
--   RB-repl→eq {n} {A} (node _ ⟪ Red , _ ⟫ _ _) .(node _ ⟪ Red , _ ⟫ _ _) rbt rbr-node = refl
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ _ _) .(node _ ⟪ Black , _ ⟫ _ _) rbt rbr-node = refl
--   RB-repl→eq {n} {A} (node _ ⟪ Red , _ ⟫ left _) .(node _ ⟪ Red , _ ⟫ left _) (rb-red _ _ x₂ x₃ x₄ rbt rbt₁) (rbr-right x x₁ t) =
--      cong (λ k → black-depth left ⊔ k ) (RB-repl→eq _ _ rbt₁ t)
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ left _) .(node _ ⟪ Black , _ ⟫ left _) (rb-black _ _ x₂ rbt rbt₁) (rbr-right x x₁ t) =
--      cong (λ k → suc (black-depth left ⊔ k)) (RB-repl→eq _ _ rbt₁ t)
--   RB-repl→eq {n} {A} (node _ ⟪ Red , _ ⟫ _ right) .(node _ ⟪ Red , _ ⟫ _ right) (rb-red _ _ x₂ x₃ x₄ rbt rbt₁) (rbr-left x x₁ t) = cong (λ k → k ⊔ black-depth right) (RB-repl→eq _ _ rbt t)
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ _ right) .(node _ ⟪ Black , _ ⟫ _ right) (rb-black _ _ x₂ rbt rbt₁) (rbr-left x x₁ t) = cong (λ k → suc (k ⊔ black-depth right)) (RB-repl→eq _ _ rbt t)
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ t₁ _) .(node _ ⟪ Black , _ ⟫ t₁ _) (rb-black _ _ x₂ rbt rbt₁) (rbr-black-right x x₁ t) = cong (λ k → suc (black-depth t₁ ⊔ k)) (RB-repl→eq _ _ rbt₁ t)
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ _ t₁) .(node _ ⟪ Black , _ ⟫ _ t₁) (rb-black _ _ x₂ rbt rbt₁) (rbr-black-left x x₁ t) = cong (λ k → suc (k ⊔ black-depth t₁)) (RB-repl→eq _ _ rbt t)
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ t₁ t₂) t₃) .(node _ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ t₄ t₂) (to-black t₃)) (rb-black _ _ x₃ (rb-red _ _ x₄ x₅ x₆ rbt rbt₂) rbt₁) (rbr-flip-ll {_} {_} {t₄} x x₁ x₂ t) = begin
--      suc (black-depth t₁ ⊔ black-depth t₂ ⊔ black-depth t₃)  ≡⟨ cong (λ k → suc (k ⊔ black-depth t₂ ⊔ black-depth t₃)) (RB-repl→eq _ _ rbt t) ⟩
--      suc (black-depth t₄ ⊔ black-depth t₂) ⊔ suc (black-depth t₃)  ≡⟨ cong (λ k → suc (black-depth t₄ ⊔ black-depth t₂) ⊔ k )  (  to-black-eq t₃ x₁ ) ⟩
--      suc (black-depth t₄ ⊔ black-depth t₂) ⊔ black-depth (to-black t₃) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ t₁ t₂) t₃) .(node _ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ t₁ t₄) (to-black t₃)) (rb-black _ _ x₄ (rb-red _ _ x₅ x₆ x₇ rbt rbt₂) rbt₁) (rbr-flip-lr {_} {_} {t₄} x x₁ x₂ x₃ t) = begin
--      suc (black-depth t₁ ⊔ black-depth t₂) ⊔ suc (black-depth t₃)  ≡⟨ cong (λ k → suc (black-depth t₁ ⊔ black-depth t₂) ⊔ k )  (  to-black-eq t₃ x₁ ) ⟩
--      suc (black-depth t₁ ⊔ black-depth t₂) ⊔ black-depth (to-black t₃) ≡⟨ cong (λ k → suc (black-depth t₁ ⊔ k ) ⊔ black-depth (to-black t₃)) (RB-repl→eq _ _ rbt₂ t) ⟩
--      suc (black-depth t₁ ⊔ black-depth t₄) ⊔ black-depth (to-black t₃) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} (node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Red , _ ⟫ (to-black t₄) (node _ ⟪ Black , _ ⟫ t₃ t₁)) (rb-black _ _ x₄ rbt (rb-red _ _ x₅ x₆ x₇ rbt₁ rbt₂)) (rbr-flip-rl {t₁} {t₂} {t₃} {t₄} x x₁ x₂ x₃ t) = begin
--      suc (black-depth t₄ ⊔ (black-depth t₂ ⊔ black-depth t₁)) ≡⟨ cong (λ k → suc (black-depth t₄ ⊔ ( k  ⊔ black-depth t₁)) ) (RB-repl→eq _ _ rbt₁ t) ⟩
--      suc (black-depth t₄ ⊔ (black-depth t₃ ⊔ black-depth t₁)) ≡⟨ cong (λ k → k ⊔ suc (black-depth t₃ ⊔ black-depth t₁)) ( to-black-eq t₄ x₁ ) ⟩
--      black-depth (to-black t₄) ⊔ suc (black-depth t₃ ⊔ black-depth t₁) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Red , _ ⟫ (to-black _) (node _ ⟪ Black , _ ⟫ _ _)) (rb-black _ _ x₃ rbt (rb-red _ _ x₄ x₅ x₆ rbt₁ rbt₂)) (rbr-flip-rr {t₁} {t₂} {t₃} {t₄} x x₁ x₂ t) = begin
--      suc (black-depth t₄ ⊔ (black-depth t₁ ⊔ black-depth t₂)) ≡⟨ cong (λ k → suc (black-depth t₄ ⊔ (black-depth t₁ ⊔ k ))) ( RB-repl→eq _ _ rbt₂ t) ⟩
--      suc (black-depth t₄ ⊔ (black-depth t₁ ⊔ black-depth t₃)) ≡⟨ cong (λ k → k ⊔ suc (black-depth t₁ ⊔ black-depth t₃)) ( to-black-eq t₄ x₁ ) ⟩
--      black-depth (to-black t₄) ⊔ suc (black-depth t₁ ⊔ black-depth t₃) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) (rb-black _ _ x₂ (rb-red _ _ x₃ x₄ x₅ rbt rbt₂) rbt₁) (rbr-rotate-ll {t₁} {t₂} {t₃} {t₄} x x₁ t) = begin
--      suc (black-depth t₂ ⊔ black-depth t₁ ⊔ black-depth t₄) ≡⟨ cong suc ( ⊔-assoc (black-depth t₂) (black-depth t₁) (black-depth t₄)) ⟩
--      suc (black-depth t₂ ⊔ (black-depth t₁ ⊔ black-depth t₄)) ≡⟨ cong (λ k → suc (k ⊔ (black-depth t₁ ⊔ black-depth t₄)) ) (RB-repl→eq _ _ rbt t) ⟩
--      suc (black-depth t₃ ⊔ (black-depth t₁ ⊔ black-depth t₄)) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) (rb-black _ _ x₂ rbt (rb-red _ _ x₃ x₄ x₅ rbt₁ rbt₂)) (rbr-rotate-rr {t₁} {t₂} {t₃} {t₄} x x₁ t) = begin
--      suc (black-depth t₄ ⊔ (black-depth t₁ ⊔ black-depth t₂)) ≡⟨ cong (λ k → suc (black-depth t₄ ⊔ (black-depth t₁ ⊔ k ))) ( RB-repl→eq _ _ rbt₂ t) ⟩
--      suc (black-depth t₄ ⊔ (black-depth t₁ ⊔ black-depth t₃)) ≡⟨ cong suc  (sym ( ⊔-assoc (black-depth t₄) (black-depth t₁) (black-depth t₃))) ⟩
--      suc (black-depth t₄ ⊔ black-depth t₁ ⊔ black-depth t₃) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} .(node kg ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ _) _) .(node kn ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ t₂) (node kg ⟪ Red , _ ⟫ t₃ _)) (rb-black .kg _ x₃ (rb-red .kp _ x₄ x₅ x₆ rbt rbt₂) rbt₁) (rbr-rotate-lr {t₀} {t₁} {uncle} t₂ t₃ kg kp kn x x₁ x₂ t) = begin
--      suc (black-depth t₀ ⊔ black-depth t₁ ⊔ black-depth uncle) ≡⟨ cong suc ( ⊔-assoc (black-depth t₀) (black-depth t₁) (black-depth uncle)) ⟩
--      suc (black-depth t₀ ⊔ (black-depth t₁ ⊔ black-depth uncle)) ≡⟨ cong (λ k → suc (black-depth t₀ ⊔ (k ⊔ black-depth uncle))) (RB-repl→eq _ _ rbt₂ t) ⟩
--      suc (black-depth t₀ ⊔ ((black-depth t₂ ⊔ black-depth t₃) ⊔ black-depth uncle)) ≡⟨ cong (λ k → suc (black-depth t₀ ⊔ k )) ( ⊔-assoc (black-depth t₂) (black-depth t₃) (black-depth uncle)) ⟩
--      suc (black-depth t₀ ⊔ (black-depth t₂ ⊔ (black-depth t₃ ⊔ black-depth uncle)))  ≡⟨ cong suc (sym ( ⊔-assoc (black-depth t₀) (black-depth t₂) (black-depth t₃ ⊔ black-depth uncle))) ⟩
--      suc (black-depth t₀ ⊔ black-depth t₂ ⊔ (black-depth t₃ ⊔ black-depth uncle)) ∎
--        where open ≡-Reasoning
--   RB-repl→eq {n} {A} .(node kg ⟪ Black , _ ⟫ _ (node kp ⟪ Red , _ ⟫ _ _)) .(node kn ⟪ Black , _ ⟫ (node kg ⟪ Red , _ ⟫ _ t₂) (node kp ⟪ Red , _ ⟫ t₃ _)) (rb-black .kg _ x₃ rbt (rb-red .kp _ x₄ x₅ x₆ rbt₁ rbt₂)) (rbr-rotate-rl {t₀} {t₁} {uncle} t₂ t₃ kg kp kn x x₁ x₂ t) = begin
--      suc (black-depth uncle ⊔ (black-depth t₁ ⊔ black-depth t₀)) ≡⟨ cong (λ k → suc (black-depth uncle ⊔ (k ⊔ black-depth t₀))) (RB-repl→eq _ _ rbt₁ t) ⟩
--      suc (black-depth uncle ⊔ ((black-depth t₂ ⊔ black-depth t₃)  ⊔ black-depth t₀)) ≡⟨ cong (λ k → suc (black-depth uncle ⊔ k)) ( ⊔-assoc (black-depth t₂) (black-depth t₃) (black-depth t₀)) ⟩
--      suc (black-depth uncle ⊔ (black-depth t₂ ⊔ (black-depth t₃ ⊔ black-depth t₀))) ≡⟨ cong suc (sym ( ⊔-assoc (black-depth uncle) (black-depth t₂) (black-depth t₃ ⊔ black-depth t₀))) ⟩
--      suc (black-depth uncle ⊔ black-depth t₂ ⊔ (black-depth t₃ ⊔ black-depth t₀)) ∎
--        where open ≡-Reasoning


RB-repl→ti>  : {n : Level} {A : Set n}  → (tree repl : bt (Color ∧ A)) → (key key₁ : ℕ) → (value : A)
     → replacedRBTree key value tree repl → key₁ < key → tr> key₁ tree → tr> key₁ repl
RB-repl→ti> = ?
--   RB-repl→ti> .leaf .(node key ⟪ Red , value ⟫ leaf leaf) key key₁ value rbr-leaf lt tr = ⟪ lt , ⟪ tt , tt ⟫ ⟫
--   RB-repl→ti> .(node key ⟪ _ , _ ⟫ _ _) .(node key ⟪ _ , value ⟫ _ _) key key₁ value (rbr-node ) lt tr = tr
--   RB-repl→ti> .(node _ ⟪ _ , _ ⟫ _ _) .(node _ ⟪ _ , _ ⟫ _ _) key key₁ value (rbr-right _ x rbt) lt tr
--      = ⟪ proj1 tr , ⟪ proj1 (proj2 tr) , RB-repl→ti> _ _ _ _ _ rbt lt (proj2 (proj2 tr)) ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ _ , _ ⟫ _ _) .(node _ ⟪ _ , _ ⟫ _ _) key key₁ value (rbr-left _ x rbt) lt tr
--      = ⟪ proj1 tr , ⟪ RB-repl→ti> _ _ _ _ _ rbt lt (proj1 (proj2 tr)) , proj2 (proj2 tr) ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ _ _) .(node _ ⟪ Black , _ ⟫ _ _) key key₁ value (rbr-black-right x _ rbt) lt tr
--      = ⟪ proj1 tr , ⟪ proj1 (proj2 tr) , RB-repl→ti> _ _ _ _ _ rbt lt (proj2 (proj2 tr)) ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ _ _) .(node _ ⟪ Black , _ ⟫ _ _) key key₁ value (rbr-black-left x _ rbt) lt tr
--      = ⟪ proj1 tr , ⟪ RB-repl→ti> _ _ _ _ _ rbt lt (proj1 (proj2 tr)) , proj2 (proj2 tr) ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ _ _) (to-black _)) key key₁ value (rbr-flip-ll x _ _ rbt) lt tr
--      = ⟪ proj1 tr , ⟪ ⟪ proj1 (proj1 (proj2 tr))  , ⟪ RB-repl→ti> _ _ _ _ _ rbt lt (proj1 (proj2 (proj1 (proj2 tr))))
--          , proj2 (proj2 (proj1 (proj2 tr))) ⟫ ⟫  , tr>-to-black (proj2 (proj2 tr)) ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ _ _) (to-black _)) key key₁ value
--      (rbr-flip-lr x _ _ _ rbt) lt ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ , tr5 ⟫ ⟫ = ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 ,  RB-repl→ti> _ _ _ _ _ rbt lt tr7 ⟫ ⟫  , tr>-to-black tr5 ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Red , _ ⟫ (to-black _) (node _ ⟪ Black , _ ⟫ _ _)) key key₁ value
--      (rbr-flip-rl x _ _ _ rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫  ⟫ ⟫ = ⟪ tr3 , ⟪ tr>-to-black tr5 , ⟪ tr4 , ⟪  RB-repl→ti> _ _ _ _ _ rbt lt tr6 , tr7 ⟫ ⟫   ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Red , _ ⟫ (to-black _) (node _ ⟪ Black , _ ⟫ _ _)) key key₁ value
--      (rbr-flip-rr x _ _ rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ ⟫ ⟫ = ⟪ tr3 , ⟪ tr>-to-black tr5 , ⟪ tr4 , ⟪ tr6 ,  RB-repl→ti> _ _ _ _ _ rbt lt tr7 ⟫ ⟫   ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) key key₁ value
--      (rbr-rotate-ll x lt2 rbt) lt ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ , tr5  ⟫ ⟫  = ⟪ tr4 , ⟪  RB-repl→ti> _ _ _ _ _ rbt lt tr6 , ⟪ tr3 , ⟪ tr7 , tr5 ⟫ ⟫ ⟫ ⟫
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) key key₁ value
--      (rbr-rotate-rr x lt2 rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫  ⟫ ⟫  = ⟪ tr4 , ⟪ ⟪ tr3 , ⟪ tr5 , tr6 ⟫ ⟫ , RB-repl→ti> _ _ _ _ _ rbt lt tr7 ⟫ ⟫
--   RB-repl→ti> (node kg ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ _) _) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node _ ⟪ Red , _ ⟫ _ _)) key key₁ value
--      (rbr-rotate-lr left right _ _ kn _ _ _ rbt) lt ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ , tr5  ⟫ ⟫  = ⟪ rr00 , ⟪ ⟪ tr4 , ⟪ tr6 , proj1 (proj2 rr01) ⟫ ⟫ , ⟪ tr3 , ⟪ proj2 (proj2 rr01) , tr5 ⟫ ⟫ ⟫ ⟫ where
--          rr01 : (key₁ < kn) ∧ tr> key₁ left  ∧ tr> key₁ right
--          rr01 = RB-repl→ti> _ _ _ _ _ rbt lt tr7
--          rr00 : key₁ < kn
--          rr00 = proj1 rr01
--   RB-repl→ti> .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node _ ⟪ Red , _ ⟫ _ _)) key key₁ value
--      (rbr-rotate-rl left right kg kp kn _ _ _ rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫  ⟫ ⟫  = ⟪ rr00 , ⟪  ⟪ tr3 , ⟪ tr5 , proj1 (proj2 rr01) ⟫ ⟫ , ⟪ tr4 , ⟪ proj2 (proj2 rr01) , tr7 ⟫ ⟫ ⟫ ⟫ where
--          rr01 : (key₁ < kn) ∧ tr> key₁ left  ∧ tr> key₁ right
--          rr01 = RB-repl→ti> _ _ _ _ _ rbt lt tr6
--          rr00 : key₁ < kn
--          rr00 = proj1 rr01

RB-repl→ti<  : {n : Level} {A : Set n}  → (tree repl : bt (Color ∧ A)) → (key key₁ : ℕ) → (value : A)
     → replacedRBTree key value tree repl → key < key₁ → tr< key₁ tree → tr< key₁ repl
RB-repl→ti< = ?
--    RB-repl→ti< .leaf .(node key ⟪ Red , value ⟫ leaf leaf) key key₁ value rbr-leaf lt tr = ⟪ lt , ⟪ tt , tt ⟫ ⟫
--    RB-repl→ti< .(node key ⟪ _ , _ ⟫ _ _) .(node key ⟪ _ , value ⟫ _ _) key key₁ value (rbr-node ) lt tr = tr
--    RB-repl→ti< .(node _ ⟪ _ , _ ⟫ _ _) .(node _ ⟪ _ , _ ⟫ _ _) key key₁ value (rbr-right _ x rbt) lt tr
--       = ⟪ proj1 tr , ⟪ proj1 (proj2 tr) , RB-repl→ti< _ _ _ _ _ rbt lt (proj2 (proj2 tr)) ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ _ , _ ⟫ _ _) .(node _ ⟪ _ , _ ⟫ _ _) key key₁ value (rbr-left _ x rbt) lt tr
--       = ⟪ proj1 tr , ⟪ RB-repl→ti< _ _ _ _ _ rbt lt (proj1 (proj2 tr)) , proj2 (proj2 tr) ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ _ _) .(node _ ⟪ Black , _ ⟫ _ _) key key₁ value (rbr-black-right x _ rbt) lt tr
--       = ⟪ proj1 tr , ⟪ proj1 (proj2 tr) , RB-repl→ti< _ _ _ _ _ rbt lt (proj2 (proj2 tr)) ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ _ _) .(node _ ⟪ Black , _ ⟫ _ _) key key₁ value (rbr-black-left x _ rbt) lt tr
--       = ⟪ proj1 tr , ⟪ RB-repl→ti< _ _ _ _ _ rbt lt (proj1 (proj2 tr)) , proj2 (proj2 tr) ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ _ _) (to-black _)) key key₁ value (rbr-flip-ll x _ _ rbt) lt tr
--       = ⟪ proj1 tr , ⟪ ⟪ proj1 (proj1 (proj2 tr))  , ⟪ RB-repl→ti< _ _ _ _ _ rbt lt (proj1 (proj2 (proj1 (proj2 tr))))
--           , proj2 (proj2 (proj1 (proj2 tr))) ⟫ ⟫  , tr<-to-black (proj2 (proj2 tr)) ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ _ _) (to-black _)) key key₁ value
--       (rbr-flip-lr x _ _ _ rbt) lt ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ , tr5 ⟫ ⟫ = ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 ,  RB-repl→ti< _ _ _ _ _ rbt lt tr7 ⟫ ⟫  , tr<-to-black tr5 ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Red , _ ⟫ (to-black _) (node _ ⟪ Black , _ ⟫ _ _)) key key₁ value
--       (rbr-flip-rl x _ _ _ rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫  ⟫ ⟫ = ⟪ tr3 , ⟪ tr<-to-black tr5 , ⟪ tr4 , ⟪  RB-repl→ti< _ _ _ _ _ rbt lt tr6 , tr7 ⟫ ⟫   ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Red , _ ⟫ (to-black _) (node _ ⟪ Black , _ ⟫ _ _)) key key₁ value
--       (rbr-flip-rr x _ _ rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ ⟫ ⟫ = ⟪ tr3 , ⟪ tr<-to-black tr5 , ⟪ tr4 , ⟪ tr6 ,  RB-repl→ti< _ _ _ _ _ rbt lt tr7 ⟫ ⟫   ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) key key₁ value
--       (rbr-rotate-ll x lt2 rbt) lt ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ , tr5  ⟫ ⟫  = ⟪ tr4 , ⟪  RB-repl→ti< _ _ _ _ _ rbt lt tr6 , ⟪ tr3 , ⟪ tr7 , tr5 ⟫ ⟫ ⟫ ⟫
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) _) key key₁ value
--       (rbr-rotate-rr x lt2 rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫  ⟫ ⟫  = ⟪ tr4 , ⟪ ⟪ tr3 , ⟪ tr5 , tr6 ⟫ ⟫ , RB-repl→ti< _ _ _ _ _ rbt lt tr7 ⟫ ⟫
--    RB-repl→ti< (node kg ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ _) _) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node _ ⟪ Red , _ ⟫ _ _)) key key₁ value
--       (rbr-rotate-lr left right _ _ kn _ _ _ rbt) lt ⟪ tr3 , ⟪ ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫ , tr5  ⟫ ⟫  = ⟪ rr00 , ⟪ ⟪ tr4 , ⟪ tr6 , proj1 (proj2 rr01) ⟫ ⟫ , ⟪ tr3 , ⟪ proj2 (proj2 rr01) , tr5 ⟫ ⟫ ⟫ ⟫ where
--           rr01 : (kn < key₁ ) ∧ tr< key₁ left  ∧ tr< key₁ right
--           rr01 = RB-repl→ti< _ _ _ _ _ rbt lt tr7
--           rr00 : kn < key₁
--           rr00 = proj1 rr01
--    RB-repl→ti< .(node _ ⟪ Black , _ ⟫ _ (node _ ⟪ Red , _ ⟫ _ _)) .(node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node _ ⟪ Red , _ ⟫ _ _)) key key₁ value
--       (rbr-rotate-rl left right kg kp kn _ _ _ rbt) lt ⟪ tr3 , ⟪ tr5 , ⟪ tr4 , ⟪ tr6 , tr7 ⟫ ⟫  ⟫ ⟫  = ⟪ rr00 , ⟪  ⟪ tr3 , ⟪ tr5 , proj1 (proj2 rr01) ⟫ ⟫ , ⟪ tr4 , ⟪ proj2 (proj2 rr01) , tr7 ⟫ ⟫ ⟫ ⟫ where
--           rr01 : (kn < key₁ ) ∧ tr< key₁ left  ∧ tr< key₁ right
--           rr01 = RB-repl→ti< _ _ _ _ _ rbt lt tr6
--           rr00 : kn < key₁
--           rr00 = proj1 rr01

RB-repl→ti : {n : Level} {A : Set n} → (tree repl : bt (Color ∧ A) ) → (key : ℕ ) → (value : A) → treeInvariant tree
       → replacedRBTree key value tree repl → treeInvariant repl
RB-repl→ti = ?
--   RB-repl→ti .leaf .(node key ⟪ Red , value ⟫ leaf leaf) key value ti rbr-leaf = t-single key ⟪ Red , value ⟫
--   RB-repl→ti .(node key ⟪ _ , _ ⟫ leaf leaf) .(node key ⟪ _ , value ⟫ leaf leaf) key value (t-single .key .(⟪ _ , _ ⟫)) (rbr-node ) = t-single key ⟪ _ , value ⟫
--   RB-repl→ti .(node key ⟪ _ , _ ⟫ leaf (node key₁ _ _ _)) .(node key ⟪ _ , value ⟫ leaf (node key₁ _ _ _)) key value
--      (t-right .key key₁ x x₁ x₂ ti) (rbr-node ) = t-right key key₁ x x₁ x₂ ti
--   RB-repl→ti .(node key ⟪ _ , _ ⟫ (node key₁ _ _ _) leaf) .(node key ⟪ _ , value ⟫ (node key₁ _ _ _) leaf) key value
--      (t-left key₁ .key x x₁ x₂ ti) (rbr-node ) = t-left key₁ key x x₁ x₂ ti
--   RB-repl→ti .(node key ⟪ _ , _ ⟫ (node key₁ _ _ _) (node key₂ _ _ _)) .(node key ⟪ _ , value ⟫ (node key₁ _ _ _) (node key₂ _ _ _)) key value
--      (t-node key₁ .key key₂ x x₁ x₂ x₃ x₄ x₅ ti ti₁) (rbr-node ) = t-node key₁ key key₂ x x₁ x₂ x₃ x₄ x₅ ti ti₁
--   RB-repl→ti (node key₁ ⟪ ca , v1 ⟫ leaf leaf) (node key₁ ⟪ ca , v1 ⟫ leaf tree@(node key₂ value₁ t t₁)) key value
--      (t-single key₁ ⟪ ca , v1 ⟫) (rbr-right _ x trb) = t-right _ _  (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₁ < key₂ ) ∧ tr> key₁ t ∧ tr> key₁ t₁
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x tt
--   RB-repl→ti (node _ ⟪ _ , _ ⟫ leaf (node key₁ _ _ _)) (node key₂ ⟪ ca , v1 ⟫ leaf (node key₃ value₁ t t₁)) key value
--      (t-right _ key₁ x₁ x₂ x₃ ti) (rbr-right _ x trb) = t-right _ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ ti trb) where
--           rr00 : (key₂ < key₃) ∧ tr> key₂ t ∧ tr> key₂ t₁
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x ⟪ x₁ , ⟪ x₂ , x₃ ⟫ ⟫
--   RB-repl→ti .(node key₂ ⟪ ca , v1 ⟫ (node key₁ value₁ t t₁) leaf) (node key₂ ⟪ ca , v1 ⟫ (node key₁ value₁ t t₁) (node key₃ value₂ t₂ t₃)) key value
--      (t-left key₁ _ x₁ x₂ x₃ ti) (rbr-right _ x trb) = t-node _ _ _ x₁ (proj1 rr00) x₂ x₃ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) ti (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₃) ∧ tr> key₂ t₂ ∧ tr> key₂ t₃
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x tt
--   RB-repl→ti .(node key₃ ⟪ ca , v1 ⟫ (node key₁ v2 t₁ t₂) (node key₂ _ _ _)) (node key₃ ⟪ ca , v1 ⟫ (node key₁ v2 t₁ t₂) (node key₄ value₁ t₃ t₄)) key value
--      (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-right _ x trb) = t-node _ _ _ x₁
--        (proj1 rr00) x₃ x₄ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) ti (RB-repl→ti _ _ _ _ ti₁ trb) where
--           rr00 : (key₃ < key₄) ∧ tr> key₃ t₃ ∧ tr> key₃ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x ⟪ x₂ , ⟪ x₅ , x₆ ⟫ ⟫
--   RB-repl→ti .(node key₁ ⟪ _ , _ ⟫ leaf leaf) (node key₁ ⟪ _ , _ ⟫ (node key₂ value₁ left left₁) leaf) key value
--      (t-single _ .(⟪ _ , _ ⟫)) (rbr-left _ x trb) = t-left _ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₁) ∧ tr< key₁ left ∧ tr< key₁ left₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x tt
--   RB-repl→ti .(node key₂ ⟪ _ , _ ⟫ leaf (node key₁ _ t₁ t₂)) (node key₂ ⟪ _ , _ ⟫ (node key₃ value₁ t t₃) (node key₁ _ t₁ t₂)) key value
--      (t-right _ key₁ x₁ x₂ x₃ ti) (rbr-left _ x trb) = t-node _ _ _ (proj1 rr00) x₁  (proj1 (proj2 rr00))(proj2 (proj2 rr00)) x₂ x₃ rr01 ti where
--           rr00 : (key₃ < key₂) ∧ tr< key₂ t ∧ tr< key₂ t₃
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x tt
--           rr01 : treeInvariant (node key₃ value₁ t t₃)
--           rr01 = RB-repl→ti _ _ _ _ t-leaf trb
--   RB-repl→ti .(node _ ⟪ _ , _ ⟫ (node key₁ _ _ _) leaf) (node key₃ ⟪ _ , _ ⟫ (node key₂ value₁ t t₁) leaf) key value
--       (t-left key₁ _ x₁ x₂ x₃ ti) (rbr-left _ x trb) = t-left key₂ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ ti trb) where
--           rr00 : (key₂ < key₃) ∧ tr< key₃ t ∧ tr< key₃ t₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x ⟪ x₁ , ⟪ x₂ , x₃ ⟫ ⟫
--   RB-repl→ti .(node key₃ ⟪ _ , _ ⟫ (node key₁ _ _ _) (node key₂ _ t₁ t₂)) (node key₃ ⟪ _ , _ ⟫ (node key₄ value₁ t t₃) (node key₂ _ t₁ t₂)) key value
--       (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-left _ x trb) = t-node _ _ _ (proj1 rr00) x₂ (proj1 (proj2 rr00))  (proj2 (proj2 rr00))  x₅ x₆ (RB-repl→ti _ _ _ _ ti trb) ti₁ where
--           rr00 : (key₄ < key₃) ∧ tr< key₃ t ∧ tr< key₃ t₃
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x ⟪ x₁ , ⟪ x₃ , x₄ ⟫ ⟫
--   RB-repl→ti .(node x₁ ⟪ Black , c ⟫ leaf leaf) (node x₁ ⟪ Black , c ⟫ leaf (node key₁ value₁ t t₁)) key value
--       (t-single x₂ .(⟪ Black , c ⟫)) (rbr-black-right x x₄ trb) = t-right _ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (x₁ < key₁) ∧ tr> x₁ t ∧ tr> x₁ t₁
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x₄ tt
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ leaf (node key₁ _ _ _)) (node key₂ ⟪ Black , _ ⟫ leaf (node key₃ value₁ t₂ t₃)) key value
--       (t-right _ key₁ x₁ x₂ x₃ ti) (rbr-black-right  x x₄ trb) = t-right _ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ ti trb) where
--           rr00 : (key₂ < key₃) ∧ tr> key₂ t₂ ∧ tr> key₂ t₃
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x₄ ⟪ x₁ , ⟪ x₂ , x₃ ⟫ ⟫
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ (node key₁ _ _ _) leaf) (node key₂ ⟪ Black , _ ⟫ (node key₁ _ _ _) (node key₃ value₁ t₂ t₃)) key value (t-left key₁ _ x₁ x₂ x₃ ti) (rbr-black-right x x₄ trb) = t-node _ _ _ x₁ (proj1 rr00) x₂ x₃ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) ti (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₃) ∧ tr> key₂ t₂ ∧ tr> key₂ t₃
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x₄ tt
--   RB-repl→ti .(node key₃ ⟪ Black , _ ⟫ (node key₁ _ _ _) (node key₂ _ _ _)) (node key₃ ⟪ Black , _ ⟫ (node key₁ _ _ _) (node key₄ value₁ t₂ t₃)) key value
--         (t-node key₁ _ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-black-right x x₇ trb) = t-node _ _ _ x₁ (proj1 rr00) x₃ x₄ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) ti (RB-repl→ti _ _ _ _ ti₁ trb) where
--           rr00 : (key₃ < key₄) ∧ tr> key₃ t₂ ∧ tr> key₃ t₃
--           rr00 = RB-repl→ti> _ _ _ _ _ trb x₇ ⟪ x₂ , ⟪ x₅ , x₆ ⟫ ⟫
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ leaf leaf) (node key₂ ⟪ Black , _ ⟫ (node key₁ value₁ t t₁) .leaf) key value
--          (t-single .key₂ .(⟪ Black , _ ⟫)) (rbr-black-left x x₇ trb) = t-left _ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₁ < key₂) ∧ tr< key₂ t ∧ tr< key₂ t₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x₇ tt
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ leaf (node key₁ _ _ _)) (node key₂ ⟪ Black , _ ⟫ (node key₃ value₁ t t₁) .(node key₁ _ _ _)) key value
--          (t-right .key₂ key₁ x₁ x₂ x₃ ti) (rbr-black-left x x₇ trb) = t-node _ _ _ (proj1 rr00) x₁ (proj1 (proj2 rr00)) (proj2 (proj2 rr00))  x₂ x₃ (RB-repl→ti _ _ _ _ t-leaf trb) ti where
--           rr00 : (key₃ < key₂) ∧ tr< key₂ t ∧ tr< key₂ t₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x₇ tt
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ (node key₁ _ _ _) leaf) (node key₂ ⟪ Black , _ ⟫ (node key₃ value₁ t t₁) .leaf) key value
--          (t-left key₁ .key₂ x₁ x₂ x₃ ti) (rbr-black-left x x₇ trb) = t-left _ _ (proj1 rr00) (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RB-repl→ti _ _ _ _ ti trb) where
--           rr00 : (key₃ < key₂) ∧ tr< key₂ t ∧ tr< key₂ t₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x₇ ⟪ x₁ , ⟪ x₂ , x₃ ⟫ ⟫
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ (node key₁ _ _ _) (node key₃ _ _ _)) (node key₂ ⟪ Black , _ ⟫ (node key₄ value₁ t t₁) .(node key₃ _ _ _)) key value
--        (t-node key₁ .key₂ key₃ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-black-left x x₇ trb) = t-node _ _ _ (proj1 rr00) x₂ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) x₅ x₆ (RB-repl→ti _ _ _ _ ti trb) ti₁ where
--           rr00 : (key₄ < key₂) ∧ tr< key₂ t ∧ tr< key₂ t₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb x₇ ⟪ x₁ , ⟪ x₃ , x₄ ⟫ ⟫
--   RB-repl→ti .(node key₂ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ t₁) leaf) (node key₂ ⟪ Red , value₁ ⟫ (node key₁ ⟪ Black , value₂ ⟫ t t₁) .(to-black leaf)) key value
--         (t-left _ .key₂ x₁ x₂ x₃ ti) (rbr-flip-ll x _ lt trb) = t-left _ _ x₁ rr00 x₃ (RTtoTI0 _ _ _ _ rr02 r-node ) where
--           rr00 : tr< key₂ t
--           rr00 = RB-repl→ti< _ _ _ _ _ trb (<-trans lt x₁) x₂
--           rr02 : treeInvariant (node key₁ ⟪ Red , value₂  ⟫ t t₁)
--           rr02 = RB-repl→ti _ _ _ _ ti (rbr-left _ lt trb)
--   RB-repl→ti (node key₂ ⟪ Black , _ ⟫ (node key₁ ⟪ Red , _ ⟫ t₀ t₁) (node key₃ ⟪ c1 , v1 ⟫  left right)) (node key₂ ⟪ Red , value₁ ⟫ (node _ ⟪ Black , value₂ ⟫ t t₁) (node key₃ ⟪ Black , v1 ⟫  left  right)) key value
--          (t-node _ .key₂ key₃ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-flip-ll x _ lt trb) = t-node _ _ _ x₁ x₂ rr00 x₄ x₅ x₆ (RTtoTI0 _ _ _ _ rr02 r-node ) (RTtoTI0 _ _ _ _ ti₁ r-node ) where
--           rr00 : tr< key₂ t
--           rr00 = RB-repl→ti< _ _ _ _ _ trb (<-trans lt x₁)  x₃
--           rr02 : treeInvariant (node key₁ ⟪ Red , value₂ ⟫ t t₁)
--           rr02  = RB-repl→ti _ _ _ _ ti (rbr-left _ lt trb)
--   RB-repl→ti (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ left right) leaf) (node key₂ ⟪ Red , v1 ⟫ (node key₃ ⟪ Black , v2 ⟫ left right₁) leaf) key value
--         (t-left _ _ x₁ x₂ x₃ ti) (rbr-flip-lr x _ lt lt2 trb) = t-left _ _ x₁ x₂ rr00 (RTtoTI0 _ _ _ _ rr02 r-node ) where
--           rr00 : tr< key₂ right₁
--           rr00 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr02 : treeInvariant (node key₃ ⟪ Red , v2 ⟫ left right₁ )
--           rr02 = RB-repl→ti _ _ _ _ ti (rbr-right _ lt trb)
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ (node key₂ ⟪ Red , v2 ⟫ t t₁) (node key₃ ⟪ c3 , v3 ⟫ t₂ t₃)) (node key₁ ⟪ Red , _ ⟫ (node _ ⟪ Black , _ ⟫ t t₄) .(to-black (node key₃ ⟪ c3 , _ ⟫ _ _))) key value
--         (t-node _ _ key₃ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-flip-lr x _ lt lt2 trb) = t-node _ _ _ x₁ x₂ x₃ rr00 x₅ x₆ (RTtoTI0 _ _ _ _ rr02 r-node ) (RTtoTI0 _ _ _ _ ti₁ r-node ) where
--           rr00 : tr< key₁ t₄
--           rr00 = RB-repl→ti< _ _ _ _ _ trb lt2 x₄
--           rr02 : treeInvariant (node key₂ ⟪ Red , v2 ⟫ t t₄)
--           rr02 = RB-repl→ti _ _ _ _ ti (rbr-right _ lt trb)
--   RB-repl→ti (node _ ⟪ Black , _ ⟫ leaf (node _ ⟪ Red , _ ⟫ t t₁)) (node key₁ ⟪ Red , v1 ⟫ .(to-black leaf) (node key₂ ⟪ Black , v2 ⟫ t₂ t₁)) key value
--         (t-right _ _ x₁ x₂ x₃ ti) (rbr-flip-rl x _ lt lt2 trb) = t-right _ _ x₁ rr00 x₃ (RTtoTI0 _ _ _ _ rr02 r-node ) where
--           rr00 : tr> key₁ t₂
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt x₂
--           rr02 : treeInvariant (node key₂ ⟪ Red , v2 ⟫ t₂ t₁)
--           rr02 = RB-repl→ti _ _ _ _ ti (rbr-left _ lt2 trb)
--   RB-repl→ti (node _ ⟪ Black , v1 ⟫ (node key₂ ⟪ c2 , v2 ⟫ t t₁) (node _ ⟪ Red , v3 ⟫ t₂ t₃)) (node key₁ ⟪ Red , _ ⟫ .(to-black (node key₂ ⟪ c2 , _ ⟫  _ _)) (node key₃ ⟪ Black , _ ⟫ t₄ t₃)) key value
--         (t-node key₂ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-flip-rl x _ lt lt2 trb) = t-node key₂ _ _ x₁ x₂ x₃ x₄ rr00 x₆ (RTtoTI0 _ _ _ _ ti r-node ) (RTtoTI0 _ _ _ _ rr02 r-node ) where
--           rr00 : tr> key₁ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt x₅
--           rr02 : treeInvariant (node key₃ ⟪ Red , v3 ⟫ t₄ t₃)
--           rr02 = RB-repl→ti _ _ _ _ ti₁ (rbr-left _ lt2 trb)
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ leaf (node key₂ ⟪ Red , v2 ⟫ t t₁)) (node _ ⟪ Red , _ ⟫ .(to-black leaf) (node _ ⟪ Black , v2 ⟫ t t₂)) key value
--       (t-right _ _ x₁ x₂ x₃ ti) (rbr-flip-rr x _ lt trb) = t-right _ _ x₁ x₂ rr00 (RTtoTI0 _ _ _ _ rr02 r-node ) where
--           rr00 : tr> key₁ t₂
--           rr00 = RB-repl→ti> _ _ _ _ _ trb (<-trans x₁ lt )  x₃
--           rr02 : treeInvariant (node key₂ ⟪ Red , v2 ⟫ t t₂)
--           rr02 = RB-repl→ti _ _ _ _ ti (rbr-right _ lt trb)
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ (node key₂ ⟪ c2 , v2 ⟫ t t₁) (node key₃ ⟪ Red , c3 ⟫ t₂ t₃)) (node _ ⟪ Red , _ ⟫ .(to-black (node key₂ ⟪ c2 , _ ⟫ _ _)) (node _ ⟪ Black , c3 ⟫ t₂ t₄)) key value
--       (t-node key₂ _ _ x₁ x₂ x₃ x₄ x₅ x₆ ti ti₁) (rbr-flip-rr x _ lt trb) = t-node key₂ _ _ x₁ x₂ x₃ x₄ x₅ rr00 (RTtoTI0 _ _ _ _ ti r-node ) (RTtoTI0 _ _ _ _ rr02 r-node ) where
--           rr00 : tr> key₁ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb (<-trans x₂ lt) x₆
--           rr02 : treeInvariant (node key₃ ⟪ Red , c3 ⟫ t₂ t₄)
--           rr02 = RB-repl→ti _ _ _ _ ti₁ (rbr-right _ lt trb)
--   RB-repl→ti {_} {A} (node k1 ⟪ Black , c1 ⟫ (node k2 ⟪ Red , c2 ⟫ .leaf .leaf) leaf) (node _ ⟪ Black , _ ⟫ (node key₁ value₁ t₂ t₃) (node _ ⟪ Red , _ ⟫ .leaf leaf)) key value (t-left _ _ x₁ x₂ x₃
--       (t-single .k2 .(⟪ Red , c2 ⟫))) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr10) x₁ (proj1 (proj2 rr10)) (proj2 (proj2 rr10)) tt tt (RB-repl→ti _ _ _ _ t-leaf trb) (t-single _ _ ) where
--           rr10 : (key₁ < k2 ) ∧ tr< k2 t₂ ∧ tr< k2 t₃
--           rr10 = RB-repl→ti< _ _ _ _ _ trb lt tt
--   RB-repl→ti {_} {A} (node k1 ⟪ Black , c1 ⟫ (node k2 ⟪ Red , c2 ⟫ .leaf .(node key₂ _ _ _)) leaf) (node _ ⟪ Black , _ ⟫ (node key₁ value₁ t₂ t₃) (node _ ⟪ Red , _ ⟫ (node key₂ value₂ t₁ t₄) leaf)) key value
--       (t-left _ _ x₁ x₂ x₃ (t-right .k2 key₂ x₄ x₅ x₆ ti)) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr10) x₁ (proj1 (proj2 rr10)) (proj2 (proj2 rr10)) ⟪ x₄ , ⟪ x₅ , x₆ ⟫ ⟫  tt rr05 rr04 where
--           rr10 : (key₁ < k2 ) ∧ tr< k2 t₂ ∧ tr< k2 t₃
--           rr10 = RB-repl→ti< _ _ _ _ _ trb lt tt
--           rr04 : treeInvariant (node k1 ⟪ Red , c1 ⟫ (node key₂ value₂ t₁ t₄) leaf)
--           rr04 = RTtoTI0 _ _ _ _ (t-left key₂ _ {_} {⟪ Red , c1 ⟫} {t₁} {t₄} (proj1 x₃) (proj1 (proj2 x₃)) (proj2 (proj2 x₃)) ti) r-node
--           rr05 : treeInvariant (node key₁ value₁ t₂ t₃)
--           rr05 = RB-repl→ti _ _ _ _ t-leaf trb
--   RB-repl→ti {_} {A} (node k1 ⟪ Black , c1 ⟫ (node k2 ⟪ Red , c2 ⟫ (node key₂ value₂ t₁ t₄) .leaf) leaf) (node _ ⟪ Black , _ ⟫ (node key₁ value₁ t₂ t₃) (node _ ⟪ Red , _ ⟫ .leaf leaf)) key value
--      (t-left _ _ x₁ x₂ x₃ (t-left key₂ .k2 x₄ x₅ x₆ ti)) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr10) x₁ (proj1 (proj2 rr10)) (proj2 (proj2 rr10)) tt tt (RB-repl→ti _ _ _ _ ti trb) (t-single _ _) where
--           rr10 : (key₁ < k2 ) ∧ tr< k2 t₂ ∧ tr< k2 t₃
--           rr10 = RB-repl→ti< _ _ _ _ _ trb lt ⟪ x₄ , ⟪ x₅ , x₆ ⟫ ⟫
--   RB-repl→ti {_} {A} (node k1 ⟪ Black , c1 ⟫ (node k2 ⟪ Red , c2 ⟫ (node key₂ value₃ left right) (node key₃ value₂ t₄ t₅)) leaf) (node _ ⟪ Black , _ ⟫ (node key₁ value₁ t₂ t₃) (node _ ⟪ Red , _ ⟫ .(node key₃ _ _ _) leaf)) key value
--        (t-left _ _ x₁ x₂ x₃ (t-node key₂ .k2 key₃ x₄ x₅ x₆ x₇ x₈ x₉ ti ti₁)) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr10) x₁ (proj1 (proj2 rr10))  (proj2 (proj2 rr10))  ⟪ x₅ , ⟪ x₈ ,  x₉ ⟫ ⟫ tt rr05 rr04 where
--           rr06 : key < k2
--           rr06 = lt
--           rr10 : (key₁ < k2) ∧ tr< k2 t₂ ∧ tr< k2 t₃
--           rr10 = RB-repl→ti< _ _ _ _ _ trb rr06 ⟪ x₄ , ⟪ x₆ , x₇ ⟫ ⟫
--           rr04 : treeInvariant (node k1 ⟪ Red , c1 ⟫ (node key₃ value₂ t₄ t₅) leaf)
--           rr04 = RTtoTI0 _ _ _ _ (t-left _ _ (proj1 x₃) (proj1 (proj2 x₃)) (proj2 (proj2 x₃)) ti₁ ) (r-left (proj1 x₃) r-node)
--           rr05 : treeInvariant (node key₁ value₁ t₂ t₃)
--           rr05 = RB-repl→ti _ _ _ _ ti trb
--   RB-repl→ti (node key₁ ⟪ Black , c1 ⟫ (node key₂ ⟪ Red , c2 ⟫ .leaf .leaf) (node key₃ v3 t₂ t₃)) (node _ ⟪ Black , _ ⟫ (node key₄ value₁ t₄ t₅) (node _ ⟪ Red , _ ⟫ .leaf (node key₃ _ _ _))) key value
--      (t-node _ _ key₃ x₁ x₂ x₃ x₄ x₅ x₆ (t-single .key₂ .(⟪ Red , c2 ⟫)) ti₁) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr00) x₁ (proj1 (proj2 rr00))  (proj2 (proj2 rr00))  tt ⟪ <-trans x₁ x₂ , ⟪ <-tr> x₅ x₁ , <-tr> x₆ x₁  ⟫ ⟫  rr02 rr03 where
--          rr00 : (key₄ < key₂) ∧ tr< key₂ t₄ ∧ tr< key₂ t₅
--          rr00 = RB-repl→ti< _ _ _ _ _ trb lt tt
--          rr02 : treeInvariant (node key₄ value₁ t₄ t₅)
--          rr02 = RB-repl→ti _ _ _ _ t-leaf trb
--          rr03 : treeInvariant (node key₁ ⟪ Red , c1 ⟫ leaf (node key₃ v3 t₂ t₃))
--          rr03 = RTtoTI0 _ _ _ _ (t-right _ _ {v3} {_} x₂ x₅ x₆ ti₁) r-node
--   RB-repl→ti (node key₁ ⟪ Black , c1 ⟫ (node key₂ ⟪ Red , c2 ⟫ leaf (node key₅ _ _ _)) (node key₃ v3 t₂ t₃)) (node _ ⟪ Black , _ ⟫ (node key₄ value₁ t₄ t₅) (node _ ⟪ Red , _ ⟫ (node key₅ value₂ t₁ t₆) (node key₃ _ _ _))) key value
--       (t-node _ _ key₃ x₁ x₂ x₃ x₄ x₅ x₆ (t-right .key₂ key₅ x₇ x₈ x₉ ti) ti₁) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr00) x₁ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) ⟪ x₇ , ⟪ x₈ , x₉ ⟫ ⟫  ⟪ <-trans x₁ x₂  , ⟪ <-tr> x₅ x₁ , <-tr> x₆ x₁ ⟫ ⟫ rr02 rr03 where
--          rr00 : (key₄ < key₂) ∧ tr< key₂ t₄ ∧ tr< key₂ t₅
--          rr00 = RB-repl→ti< _ _ _ _ _ trb lt tt
--          rr02 : treeInvariant (node key₄ value₁ t₄ t₅)
--          rr02 = RB-repl→ti _ _ _ _ t-leaf trb
--          rr03 : treeInvariant (node key₁ ⟪ Red , c1 ⟫ (node key₅ value₂ t₁ t₆) (node key₃ v3 t₂ t₃))
--          rr03 = RTtoTI0 _ _ _ _ (t-node _ _ _ {_} {v3} {_} {_} {_} {_} {_} (proj1 x₄) x₂ (proj1 (proj2 x₄)) (proj2 (proj2 x₄)) x₅ x₆ ti ti₁ ) r-node
--   RB-repl→ti (node key₁ ⟪ Black , c1 ⟫ (node key₂ ⟪ Red , c2 ⟫ .(node key₅ _ _ _) .leaf) (node key₃ v3 t₂ t₃)) (node _ ⟪ Black , _ ⟫ (node key₄ value₁ t₄ t₅) (node _ ⟪ Red , _ ⟫ .leaf (node key₃ _ _ _))) key value (t-node _ _ key₃ x₁ x₂ x₃ x₄ x₅ x₆
--       (t-left key₅ .key₂ x₇ x₈ x₉ ti) ti₁) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr00) x₁ (proj1 (proj2 rr00)) (proj2 (proj2 rr00))  tt ⟪ <-trans x₁ x₂  , ⟪ <-tr> x₅ x₁  , <-tr> x₆ x₁ ⟫ ⟫  rr02 rr04 where
--           rr00 : (key₄ < key₂) ∧ tr< key₂ t₄ ∧ tr< key₂ t₅
--           rr00 = RB-repl→ti< _ _ _ _ _ trb lt ⟪ x₇ , ⟪ x₈ , x₉ ⟫ ⟫
--           rr02 : treeInvariant (node key₄ value₁ t₄ t₅)
--           rr02 = RB-repl→ti _ _ _ _ ti trb
--           rr03 : treeInvariant (node key₁ ⟪ Red , c1 ⟫ (node key₅ _ _ _) (node key₃ v3 t₂ t₃))
--           rr03 = RTtoTI0 _ _ _ _ (t-node _ _ _ {_} {v3} {_} {_} {_} {_} {_} (proj1 x₃) x₂ (proj1 (proj2 x₃)) (proj2 (proj2 x₃)) x₅ x₆ ti ti₁) r-node
--           rr04 :  treeInvariant (node key₁ ⟪ Red , c1 ⟫ leaf (node key₃ v3 t₂ t₃))
--           rr04 = RTtoTI0 _ _ _ _ (t-right _ _ {v3} {_} x₂ x₅ x₆ ti₁) r-node
--   RB-repl→ti {_} {A} (node key₁ ⟪ Black , c1 ⟫ (node key₂ ⟪ Red , c2 ⟫ .(node key₅ _ _ _) (node key₆ value₆ t₆ t₇)) (node key₃ v3 t₂ t₃)) (node _ ⟪ Black , _ ⟫ (node key₄ value₁ t₄ t₅) (node _ ⟪ Red , _ ⟫ .(node key₆ _ _ _) (node key₃ _ _ _))) key value
--     (t-node _ _ key₃ x₁ x₂ x₃ x₄ x₅ x₆ (t-node key₅ .key₂ key₆ x₇ x₈ x₉ x₁₀ x₁₁ x₁₂ ti ti₂) ti₁) (rbr-rotate-ll x lt trb) = t-node _ _ _ (proj1 rr00) x₁ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) ⟪ x₈ , ⟪ x₁₁ , x₁₂ ⟫ ⟫  ⟪ <-trans x₁ x₂ , ⟪ rr05 , <-tr> x₆ x₁ ⟫ ⟫ rr02 rr03 where
--           rr00 : (key₄ < key₂) ∧ tr< key₂ t₄ ∧ tr< key₂ t₅
--           rr00 = RB-repl→ti< _ _ _ _ _ trb lt ⟪ x₇ , ⟪ x₉ , x₁₀ ⟫ ⟫
--           rr02 : treeInvariant (node key₄ value₁ t₄ t₅)
--           rr02 = RB-repl→ti _ _ _ _ ti trb
--           rr03 : treeInvariant (node key₁ ⟪ Red , c1 ⟫ (node key₆ value₆ t₆ t₇) (node key₃ v3 t₂ t₃))
--           rr03 = RTtoTI0 _ _ _ _(t-node _ _ _ {_} {value₁} {_} {_} {_} {_} {_} (proj1 x₄) x₂ (proj1 (proj2 x₄)) (proj2 (proj2 x₄)) x₅ x₆ ti₂ ti₁) r-node
--           rr05 : tr> key₂ t₂
--           rr05 = <-tr> x₅ x₁
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ leaf (node key₂ ⟪ Red , v2 ⟫ leaf leaf)) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₃ value₁ t₃ t₄)) key value
--       (t-right .key₁ .key₂ x₁ x₂ x₃ (t-single .key₂ .(⟪ Red , _ ⟫))) (rbr-rotate-rr x lt trb)
--         = t-node _ _ _ x₁ (proj1 rr00) tt tt (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-single _ _) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₃) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt tt
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ leaf (node key₂ ⟪ Red , v2 ⟫ leaf (node key₃ value₃ t t₁))) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₄ value₁ t₃ t₄)) key value
--      (t-right .key₁ .key₂ x₁ x₂ x₃ (t-right .key₂ key₃ x₄ x₅ x₆ ti)) (rbr-rotate-rr x lt trb)
--         = t-node _ _ _ x₁ (proj1 rr00) tt tt (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-single _ _ ) (RB-repl→ti _ _ _ _ ti trb) where
--           rr00 : (key₂ < key₄) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt ⟪ x₄ , ⟪ x₅ , x₆ ⟫ ⟫
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ leaf (node key₂ ⟪ Red , v2 ⟫ (node key₃ _ _ _) leaf)) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₄ value₁ t₃ t₄)) key value
--       (t-right .key₁ .key₂ x₁ x₂ x₃ (t-left key₃ .key₂ x₄ x₅ x₆ ti)) (rbr-rotate-rr x lt trb)
--          = t-node _ _ _ x₁ (proj1 rr00) tt ⟪ x₄ , ⟪ x₅ , x₆ ⟫ ⟫ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-right _ _ (proj1 x₂) (proj1 (proj2 x₂)) (proj2 (proj2 x₂)) ti)  (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₄) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt tt
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ leaf (node key₂ ⟪ Red , v2 ⟫ (node key₃ _ _ _) (node key₄ _ _ _))) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₅ value₁ t₃ t₄)) key value
--       (t-right .key₁ .key₂ x₁ x₂ x₃ (t-node key₃ .key₂ key₄ x₄ x₅ x₆ x₇ x₈ x₉ ti ti₁)) (rbr-rotate-rr x lt trb) = t-node _ _ _ x₁ (proj1 rr00) tt ⟪ x₄ , ⟪ x₆ , x₇ ⟫ ⟫ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-right _ _ (proj1 x₂) (proj1 (proj2 x₂)) (proj2 (proj2 x₂)) ti) (RB-repl→ti _ _ _ _ ti₁ trb) where
--           rr00 : (key₂ < key₅) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt ⟪ x₅ , ⟪ x₈ , x₉ ⟫ ⟫
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ .(node key₃ _ _ _) (node key₂ ⟪ Red , v2 ⟫ .leaf .leaf)) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₄ value₁ t₃ t₄)) key value
--      (t-node key₃ .key₁ .key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti (t-single .key₂ .(⟪ Red , v2 ⟫))) (rbr-rotate-rr x lt trb)
--        = t-node _ _ _ x₂ (proj1 rr00) ⟪ <-trans x₁ x₂ , ⟪ >-tr< x₃ x₂ , >-tr< x₄ x₂ ⟫ ⟫  tt (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-left _ _ x₁ x₃ x₄ ti) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₄) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt tt
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ (node key₃ v3 t t₁) (node key₂ ⟪ Red , v2 ⟫ leaf (node key₄ _ _ _))) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₅ value₁ t₃ t₄)) key value
--      (t-node key₃ .key₁ .key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti (t-right .key₂ key₄ x₇ x₈ x₉ ti₁)) (rbr-rotate-rr x lt trb)
--         = t-node _ _ _ x₂ (proj1 rr00) ⟪ <-trans x₁ x₂ , ⟪ >-tr< x₃ x₂ , >-tr< x₄ x₂ ⟫ ⟫ tt (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-left _ _ x₁ x₃ x₄ ti) (RB-repl→ti _ _ _ _ ti₁ trb) where
--           rr00 : (key₂ < key₅) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt ⟪ x₇ , ⟪ x₈ , x₉ ⟫ ⟫
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ (node key₃ _ _ _) (node key₂ ⟪ Red , v2 ⟫ (node key₄ _ _ _) leaf)) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₅ value₁ t₃ t₄)) key value
--      (t-node key₃ key₁ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti (t-left key₄ key₂ x₇ x₈ x₉ ti₁)) (rbr-rotate-rr x lt trb)
--         = t-node _ _ _ x₂ (proj1 rr00) ⟪ <-trans x₁ x₂ , ⟪ >-tr< x₃ x₂  , >-tr< x₄ x₂ ⟫ ⟫ ⟪ x₇ , ⟪ x₈ , x₉ ⟫ ⟫ (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (t-node _ _ _  x₁ (proj1 x₅) x₃ x₄ (proj1 (proj2 x₅)) (proj2 (proj2 x₅)) ti ti₁) (RB-repl→ti _ _ _ _ t-leaf trb) where
--           rr00 : (key₂ < key₅) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt tt
--   RB-repl→ti (node key₁ ⟪ Black , v1 ⟫ (node key₃ _ _ _) (node key₂ ⟪ Red , v2 ⟫ (node key₄ _ left right) (node key₅ _ _ _))) (node _ ⟪ Black , _ ⟫ (node _ ⟪ Red , _ ⟫ _ _) (node key₆ value₁ t₃ t₄)) key value
--      (t-node key₃ key₁ key₂ x₁ x₂ x₃ x₄ x₅ x₆ ti (t-node key₄ key₂ key₅ x₇ x₈ x₉ x₁₀ x₁₁ x₁₂ ti₁ ti₂)) (rbr-rotate-rr x lt trb)
--        = t-node _ _ _ x₂ (proj1 rr00) ⟪ <-trans x₁ x₂ , ⟪ >-tr< x₃ x₂ , >-tr< x₄ x₂ ⟫ ⟫  ⟪ x₇ , ⟪ x₉ , x₁₀ ⟫ ⟫  (proj1 (proj2 rr00)) (proj2 (proj2 rr00)) (RTtoTI0 _ _ _ _ (t-node _ _ _ {_} {value₁} x₁ (proj1 x₅) x₃ x₄  (proj1 (proj2 x₅)) (proj2 (proj2 x₅)) ti ti₁ ) r-node )
--        (RB-repl→ti _ _ _ _ ti₂ trb) where
--           rr00 : (key₂ < key₆) ∧ tr> key₂ t₃ ∧ tr> key₂ t₄
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt ⟪ x₈ , ⟪ x₁₁ , x₁₂ ⟫ ⟫
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ leaf leaf) .leaf) (node kn ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ leaf) (node kg ⟪ Red , _ ⟫ leaf _)) .kn _ (t-left .kp .kg x x₁ x₂ ti) (rbr-rotate-lr .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 tt tt tt tt (t-single _ _) (t-single _ _)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ (node key₁ value₁ t t₁) leaf) .leaf) (node kn ⟪ Black , v3 ⟫ (node kp ⟪ Red , _ ⟫ _ leaf) (node kg ⟪ Red , _ ⟫ leaf _)) .kn .v3 (t-left .kp .kg x x₁ x₂ (t-left .key₁ .kp x₃ x₄ x₅ ti)) (rbr-rotate-lr .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) =
--       t-node _ _ _ lt1 lt2 ⟪ <-trans x₃ lt1  , ⟪ >-tr< x₄ lt1  , >-tr< x₅ lt1 ⟫ ⟫  tt tt tt (t-left _ _ x₃ x₄ x₅ ti) (t-single _ _)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .leaf (node key₁ .(⟪ Red , _ ⟫) .leaf .leaf)) .leaf) (node .key₁ ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ leaf) (node kg ⟪ Red , _ ⟫ leaf _)) .key₁ _ (t-left .kp .kg x x₁ x₂ (t-right .kp .key₁ x₃ x₄ x₅ ti)) (rbr-rotate-lr .leaf .leaf kg kp .key₁ _ lt1 lt2 (rbr-node )) = t-node _ _ _ lt1 lt2 tt tt tt tt (t-single _ _) (t-single _ _)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .leaf (node key₁ value₁ t₁ t₂)) .leaf) (node kn ⟪ Black , value₃ ⟫ (node kp ⟪ Red , _ ⟫ _ leaf) (node kg ⟪ Red , _ ⟫ (node key₂ value₂ t₄ t₅) t₆)) key value (t-left .kp .kg x x₁ x₂ (t-right .kp .key₁ x₃ x₄ x₅ ti)) (rbr-rotate-lr .leaf .(node key₂ value₂ t₄ t₅) kg kp kn _ lt1 lt2 trb) =
--      t-node _ _ _ (proj1 rr00) (proj1 rr01) tt tt rr03 tt (t-single _ _) (t-left _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) (treeRightDown _ _ ( RB-repl→ti _ _ _ _ ti trb))) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ((kp < key₂) ∧ tr> kp t₄ ∧ tr> kp t₅ )
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₃ , ⟪ x₄ , x₅ ⟫ ⟫
--           rr01 : (kn < kg) ∧ ⊤ ∧ ((key₂ < kg ) ∧ tr< kg t₄ ∧ tr< kg t₅ ) -- tr< kg (node key₂ value₂ t₄ t₅)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--           rr02 = proj2 (proj2 rr01)
--           rr03 : (kn < key₂) ∧ tr> kn t₄ ∧ tr> kn t₅
--           rr03 with RB-repl→ti _ _ _ _ ti trb
--           ... | t-right .kn .key₂ x x₁ x₂ t = ⟪ x , ⟪ x₁ , x₂ ⟫ ⟫
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .leaf (node key₁ value₁ t₁ t₂)) .leaf) (node kn ⟪ Black , value₃ ⟫ (node kp ⟪ Red , _ ⟫ _ (node key₂ value₂ t₃ t₅)) (node kg ⟪ Red , _ ⟫ leaf _)) key value (t-left .kp .kg x x₁ x₂ (t-right .kp .key₁ x₃ x₄ x₅ ti)) (rbr-rotate-lr .(node key₂ value₂ t₃ t₅) .leaf kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-left .key₂ .kn x₆ x₇ x₈ t =
--      t-node _ _ _ (proj1 rr00) (proj1 rr01) tt ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫ tt tt (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) t) (t-single _ _) where
--           rr00 : (kp < kn) ∧ ((kp < key₂) ∧ tr> kp t₃ ∧ tr> kp t₅) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₃ , ⟪ x₄ , x₅ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₂ < kg) ∧ tr< kg t₃ ∧ tr< kg t₅) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .leaf (node key₁ value₁ t₁ t₂)) .leaf) (node kn ⟪ Black , value₄ ⟫ (node kp ⟪ Red , _ ⟫ _ (node key₂ value₂ t₃ t₅)) (node kg ⟪ Red , _ ⟫ (node key₃ value₃ t₄ t₆) _)) key value (t-left .kp .kg x x₁ x₂ (t-right .kp .key₁ x₃ x₄ x₅ ti)) (rbr-rotate-lr .(node key₂ value₂ t₃ t₅) .(node key₃ value₃ t₄ t₆) kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-node .key₂ .kn .key₃ x₆ x₇ x₈ x₉ x₁₀ x₁₁ t t₇ = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt ⟪ x₆ , ⟪ x₈ , x₉ ⟫ ⟫ ⟪ x₇ , ⟪ x₁₀ , x₁₁ ⟫ ⟫ tt (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) t) (t-left _ _ (proj1 rr03) (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) t₇) where
--           rr00 : (kp < kn) ∧ ((kp < key₂) ∧ tr> kp t₃ ∧ tr> kp t₅) ∧ ((kp < key₃) ∧ tr> kp t₄ ∧ tr> kp t₆ )
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₃ , ⟪ x₄ , x₅ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₂ < kg) ∧ tr< kg t₃ ∧ tr< kg t₅) ∧ ((key₃ < kg) ∧ tr< kg t₄ ∧ tr< kg t₆ )
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--           rr03 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ (node key₂ value₂ t₅ t₆) (node key₁ value₁ t₁ t₂)) leaf) (node kn ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ t₃) (node kg ⟪ Red , _ ⟫ t₄ _)) key value (t-left .kp .kg x x₁ x₂ (t-node key₂ .kp .key₁ x₃ x₄ x₅ x₆ x₇ x₈ ti ti₁)) (rbr-rotate-lr t₃ t₄ kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti₁ trb
--   ... | t-single .kn .(⟪ Red , _ ⟫) = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₃ (proj1 rr00)  , ⟪ >-tr< x₅ (proj1 rr00) , >-tr< x₆ (proj1 rr00) ⟫ ⟫  tt tt tt (t-left _ _ x₃ x₅ x₆ ti) (t-single _ _) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₄ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr01 : (kn < kg) ∧ ⊤ ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--   ... | t-right .kn key₃ {v1} {v3} {t₇} {t₈} x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₃ (proj1 rr00) , ⟪ >-tr< x₅ (proj1 rr00) , >-tr< x₆ (proj1 rr00) ⟫ ⟫  tt ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫ tt (t-left _ _ x₃ x₅ x₆ ti) (t-left _ _ (proj1 rr03) (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) (treeRightDown _ _ (RB-repl→ti _ _ _ _ ti₁ trb))) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ((kp < key₃) ∧ tr> kp t₇ ∧ tr> kp t₈) -- tr> kp (node key₃ v3 t₇ t₈)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₄ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ⊤ ∧ ((key₃ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) -- tr< kg (node key₃ v3 t₇ t₈)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--           rr03 = proj2 (proj2 rr01)
--   ... | t-left key₃ .kn {v1} {v3} {t₇} {t₈} x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₃ (proj1 rr00) , ⟪ >-tr< x₅ (proj1 rr00) , >-tr< x₆ (proj1 rr00) ⟫ ⟫  ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫ tt tt (t-node key₂ kp key₃ x₃ (proj1 rr02) x₅ x₆ (proj1 (proj2 rr02))  (proj2 (proj2 rr02)) ti (treeLeftDown _ _ (RB-repl→ti _ _ _ _ ti₁ trb))) (t-single _ _) where
--           rr00 : (kp < kn) ∧ ((kp < key₃) ∧ tr> kp t₇ ∧ tr> kp t₈) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₄ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₃ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--   ... | t-node key₃ .kn key₄ {v0} {v1} {v2} {t₇} {t₈} {t₉}  {t₁₀} x₉ x₁₀ x₁₁ x₁₂ x₁₃ x₁₄ t t₃ = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₃ (proj1 rr00)  , ⟪ >-tr< x₅ (proj1 rr00) , >-tr< x₆ (proj1 rr00) ⟫ ⟫  ⟪ x₉ , ⟪ x₁₁ , x₁₂ ⟫ ⟫  ⟪ x₁₀ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  tt (t-node _ _ _ x₃ (proj1 rr02) x₅ x₆ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti (treeLeftDown _ _ (RB-repl→ti _ _ _ _ ti₁ trb))) (t-left _ _ (proj1 rr03) (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) t₃) where
--           rr00 : (kp < kn) ∧ ((kp < key₃) ∧ tr> kp t₇ ∧ tr> kp t₈) ∧ ((kp < key₄) ∧ tr> kp t₉ ∧ tr> kp t₁₀)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₄ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₃ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) ∧ ((key₄ < kg) ∧ tr< kg t₉ ∧ tr< kg t₁₀)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₂
--           rr03 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .leaf leaf) (node key₂ value₂ t₅ t₆)) (node kn ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ .leaf) (node kg ⟪ Red , _ ⟫ .leaf _)) .kn _ (t-node .kp .kg key₂ x x₁ x₂ x₃ x₄ x₅ (t-single .kp .(⟪ Red , v2 ⟫)) ti₁) (rbr-rotate-lr .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 tt tt tt ⟪ <-trans lt2 x₁  , ⟪ <-tr> x₄ lt2  , <-tr> x₅ lt2 ⟫ ⟫  (t-single _ _) (t-right _ _ x₁ x₄ x₅ ti₁)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .(node key _ _ _) leaf) (node key₂ value₂ t₅ t₆)) (node kn ⟪ Black , _ ⟫ (node kp ⟪ Red , _ ⟫ _ .leaf) (node kg ⟪ Red , _ ⟫ .leaf _)) .kn _ (t-node .kp .kg key₂ x x₁ x₂ x₃ x₄ x₅ (t-left key .kp x₆ x₇ x₈ ti) ti₁) (rbr-rotate-lr .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 ⟪ <-trans x₆ lt1 , ⟪ >-tr< x₇ lt1 , >-tr< x₈ lt1 ⟫ ⟫  tt tt ⟪ <-trans lt2 x₁ , ⟪ <-tr> x₄ lt2 , <-tr> x₅ lt2 ⟫ ⟫ (t-left _ _ x₆ x₇ x₈ ti) (t-right _ _ x₁ x₄ x₅ ti₁)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .leaf (node key₁ value₁ t₁ t₂)) .(node key₂ _ _ _)) (node kn ⟪ Black , value₃ ⟫ (node kp ⟪ Red , _ ⟫ _ t₃) (node kg ⟪ Red , _ ⟫ t₄ _)) key value (t-node .kp .kg key₂ x x₁ x₂ x₃ x₄ x₅ (t-right .kp .key₁ x₆ x₇ x₈ ti) ti₁) (rbr-rotate-lr t₃ t₄ kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-single .kn .(⟪ Red , value₃ ⟫) = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt tt tt ⟪ <-trans (proj1 rr01) x₁  , ⟪ <-tr> x₄ (proj1 rr01) , <-tr> x₅ (proj1 rr01) ⟫ ⟫  (t-single _ _) (t-right _ _ x₁ x₄ x₅ ti₁) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr01 : (kn < kg) ∧ ⊤ ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--   ... | t-right .kn key₃ {v1} {v3} {t₇} {t₈} x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt tt ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₁ , ⟪ <-tr> x₄ (proj1 rr01)  , <-tr> x₅ (proj1 rr01) ⟫ ⟫  (t-single _ _) (t-node _ _ _ (proj1 rr03) x₁ (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) x₄ x₅  (treeRightDown _ _ (RB-repl→ti _ _ _ _ ti trb)) ti₁) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ((kp < key₃) ∧ tr> kp t₇ ∧ tr> kp t₈)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ⊤ ∧ ((key₃ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr03 = proj2 (proj2 rr01)
--   ... | t-left key₃ .kn {v1} {v3} {t₇} {t₈} x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt ⟪ x₉ , ⟪ x₁₀  , x₁₁ ⟫ ⟫ tt ⟪ <-trans (proj1 rr01) x₁ , ⟪ <-tr> x₄ (proj1 rr01)  , <-tr> x₅ (proj1 rr01) ⟫ ⟫  (t-right _ _  (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) (treeLeftDown _ _ (RB-repl→ti _ _ _ _  ti trb))) (t-right _ _ x₁ x₄ x₅ ti₁) where
--           rr00 : (kp < kn) ∧ ((kp < key₃) ∧ tr> kp t₇ ∧ tr> kp t₈) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₃ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr03 = proj1 (proj2 rr01)
--   ... | t-node key₃ .kn key₄ {v0} {v1} {v2} {t₇} {t₈} {t₉}  {t₁₀} x₉ x₁₀ x₁₁ x₁₂ x₁₃ x₁₄ t t₃ = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt ⟪ x₉ , ⟪ x₁₁ , x₁₂ ⟫ ⟫  ⟪ x₁₀ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₁  , ⟪ <-tr> x₄ (proj1 rr01)  , <-tr> x₅ (proj1 rr01)  ⟫ ⟫ (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02))  (treeLeftDown _ _ (RB-repl→ti _ _ _ _ ti trb))) (t-node _ _ _ (proj1 rr03) x₁ (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) x₄ x₅ t₃ ti₁)  where
--           rr00 : (kp < kn) ∧ ((kp < key₃) ∧ tr> kp t₇ ∧ tr> kp t₈) ∧ ((kp < key₄) ∧ tr> kp t₉ ∧ tr> kp t₁₀)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₃ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) ∧ ((key₄ < kg) ∧ tr< kg t₉ ∧ tr< kg t₁₀)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr03 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , v1 ⟫ (node kp ⟪ Red , v2 ⟫ .(node key₃ _ _ _) (node key₁ value₁ t₁ t₂)) .(node key₂ _ _ _)) (node kn ⟪ Black , value₃ ⟫ (node kp ⟪ Red , _ ⟫ _ t₃) (node kg ⟪ Red , _ ⟫ t₄ _)) key value (t-node .kp .kg key₂ x x₁ x₂ x₃ x₄ x₅ (t-node key₃ .kp .key₁ x₆ x₇ x₈ x₉ x₁₀ x₁₁ ti ti₂) ti₁) (rbr-rotate-lr t₃ t₄ kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti₂ trb
--   ... | t-single .kn .(⟪ Red , value₃ ⟫) = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₆ (proj1 rr00)  , ⟪ >-tr< x₈ (proj1 rr00) , >-tr< x₉ (proj1 rr00) ⟫ ⟫  tt tt ⟪ <-trans (proj1 rr01) x₁ , ⟪ <-tr> x₄ (proj1 rr01)  , <-tr> x₅ (proj1 rr01) ⟫ ⟫  (t-left _ _ x₆ x₈ x₉ ti) (t-right _ _ x₁ x₄ x₅ ti₁) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₇ , ⟪ x₁₀ , x₁₁ ⟫ ⟫
--           rr01 : (kn < kg) ∧ ⊤ ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--   ... | t-right .kn key₄ {v1} {v3} {t₇} {t₈} x₁₂ x₁₃ x₁₄ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₆ (proj1 rr00) , ⟪ >-tr< x₈ (proj1 rr00) , >-tr< x₉ (proj1 rr00) ⟫ ⟫  tt ⟪ x₁₂ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₁ , ⟪ <-tr> x₄ (proj1 rr01) , <-tr> x₅ (proj1 rr01) ⟫ ⟫  (t-left _ _ x₆ x₈ x₉ ti) (t-node _ _ _ (proj1 rr03) x₁ (proj1 (proj2 rr03))  (proj2 (proj2 rr03)) x₄ x₅ (treeRightDown _ _ (RB-repl→ti _ _ _ _ ti₂ trb)) ti₁ ) where
--           rr00 : (kp < kn) ∧ ⊤ ∧ ((kp < key₄) ∧ tr> kp t₇ ∧ tr> kp t₈)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₇ , ⟪ x₁₀ , x₁₁ ⟫ ⟫
--           rr02 = proj2 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ⊤ ∧ ((key₄ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr03 = proj2 (proj2 rr01)
--   ... | t-left key₄ .kn {v1} {v3} {t₇} {t₈} x₁₂ x₁₃ x₁₄ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₆ (proj1 rr00) , ⟪ >-tr< x₈ (proj1 rr00) , >-tr< x₉ (proj1 rr00) ⟫ ⟫  ⟪ x₁₂ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  tt ⟪ <-trans (proj1 rr01) x₁ , ⟪ <-tr> x₄ (proj1 rr01) , <-tr> x₅ (proj1 rr01) ⟫ ⟫  (t-node _ _ _ x₆ (proj1 rr02) x₈ x₉ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti (treeLeftDown _ _ (RB-repl→ti _ _ _ _ ti₂ trb)) )  (t-right _ _ x₁ x₄ x₅ ti₁) where
--           rr00 : (kp < kn) ∧ ((kp < key₄) ∧ tr> kp t₇ ∧ tr> kp t₈) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₇ , ⟪ x₁₀ , x₁₁ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₄ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr03 = proj1 (proj2 rr01)
--   ... | t-node key₄ .kn key₅ {v0} {v1} {v2} {t₇} {t₈} {t₉}  {t₁₀}x₁₂ x₁₃ x₁₄ x₁₅ x₁₆ x₁₇ t t₃ = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x₆ (proj1 rr00)  , ⟪ >-tr< x₈ (proj1 rr00)   , >-tr< x₉ (proj1 rr00) ⟫ ⟫  ⟪ x₁₂ , ⟪ x₁₄ , x₁₅ ⟫ ⟫  ⟪ x₁₃ , ⟪ x₁₆ , x₁₇ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₁ , ⟪ <-tr> x₄ (proj1 rr01) , <-tr> x₅ (proj1 rr01)  ⟫ ⟫  (t-node _ _ _ x₆ (proj1 rr02) x₈ x₉ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti t ) (t-node _ _ _ (proj1 rr04) x₁ (proj1 (proj2 rr04)) (proj2 (proj2 rr04)) x₄ x₅ (treeRightDown _ _ (RB-repl→ti _ _ _ _ ti₂ trb)) ti₁ ) where
--           rr00 : (kp < kn) ∧ ((kp < key₄) ∧ tr> kp t₇ ∧ tr> kp t₈) ∧ ((kp < key₅) ∧ tr> kp t₉ ∧ tr> kp t₁₀)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 ⟪ x₇ , ⟪ x₁₀ , x₁₁ ⟫ ⟫
--           rr02 = proj1 (proj2 rr00)
--           rr05 = proj2 (proj2 rr00)
--           rr01 : (kn < kg) ∧ ((key₄ < kg) ∧ tr< kg t₇ ∧ tr< kg t₈) ∧ ((key₅ < kg) ∧ tr< kg t₉ ∧ tr< kg t₁₀)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 x₃
--           rr03 = proj1 (proj2 rr01)
--           rr04 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .leaf leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf leaf) (node kp ⟪ Red , _ ⟫ leaf _)) .kn .vn (t-right .kg .kp x x₁ x₂ ti) (rbr-rotate-rl .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 tt tt tt tt (t-single _ _) (t-single _ _)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node kn ⟪ Red , _ ⟫ leaf leaf) leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf leaf) (node kp ⟪ Red , _ ⟫ leaf _)) .kn .vn (t-right .kg .kp x x₁ x₂ ti) (rbr-rotate-rl .leaf .leaf kg kp kn _ lt1 lt2 (rbr-node )) = t-node _ _ _ lt1 lt2 tt tt tt tt (t-single _ _) (t-single _ _)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .leaf (node key₁ value₁ t₅ t₆))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf leaf) (node kp ⟪ Red , _ ⟫ leaf _)) .kn .vn (t-right .kg .kp x x₁ x₂ (t-right .kp .key₁ x₃ x₄ x₅ ti)) (rbr-rotate-rl .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 tt tt tt ⟪ <-trans lt2 x₃ , ⟪ <-tr> x₄ lt2 , <-tr> x₅ lt2 ⟫ ⟫  (t-single _ _) (t-right _ _ x₃ x₄ x₅ ti)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) (node key₁ value₁ t₅ t₆))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf leaf) (node kp ⟪ Red , _ ⟫ leaf _)) key value (t-right .kg .kp x x₁ x₂ (t-node key₂ .kp .key₁ x₃ x₄ x₅ x₆ x₇ x₈ ti ti₁)) (rbr-rotate-rl .leaf .leaf kg kp kn _ lt1 lt2 trb) = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt tt tt ⟪ <-trans (proj1 rr01) x₄ , ⟪ <-tr> x₇ (proj1 rr01) , <-tr> x₈ (proj1 rr01) ⟫ ⟫  (t-single _ _) (t-right _ _ x₄ x₇ x₈ ti₁) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr01 : (kn < kp) ∧ ⊤ ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₅ , x₆ ⟫ ⟫
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) .leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf (node key₁ value₁ t₂ t₃)) (node kp ⟪ Red , _ ⟫ leaf _)) key value (t-right .kg .kp x x₁ x₂ (t-left key₂ .kp x₃ x₄ x₅ ti)) (rbr-rotate-rl .(node key₁ value₁ t₂ t₃) .leaf kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-left .key₁ .kn x₆ x₇ x₈ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫ tt tt  (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) t) (t-single _ _) where
--           rr00 : (kg < kn) ∧ ((kg < key₁) ∧ tr> kg t₂ ∧ tr> kg t₃) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₁ < kp) ∧ tr< kp t₂ ∧ tr< kp t₃) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₄ , x₅ ⟫ ⟫
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) .(node key₃ _ _ _))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf (node key₁ value₁ t₂ t₃)) (node kp ⟪ Red , _ ⟫ leaf _)) key value (t-right .kg .kp x x₁ x₂ (t-node key₂ .kp key₃ x₃ x₄ x₅ x₆ x₇ x₈ ti ti₁)) (rbr-rotate-rl .(node key₁ value₁ t₂ t₃) .leaf kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-left .key₁ .kn x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01) tt ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫ tt ⟪ <-trans (proj1 rr01) x₄  , ⟪ <-tr> x₇ (proj1 rr01)  , <-tr> x₈ (proj1 rr01) ⟫ ⟫   (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) t) (t-right _ _ x₄ x₇ x₈ ti₁) where
--           rr00 : (kg < kn) ∧ ((kg < key₁) ∧ tr> kg t₂ ∧ tr> kg t₃) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₁ < kp) ∧ tr< kp t₂ ∧ tr< kp t₃) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₅ , x₆ ⟫ ⟫
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .leaf .leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .(node key₁ _ _ _) .leaf) (node kp ⟪ Red , _ ⟫ leaf _)) .kn .vn (t-node key₁ .kg .kp x x₁ x₂ x₃ x₄ x₅ ti (t-single .kp .(⟪ Red , vp ⟫))) (rbr-rotate-rl .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 ⟪ <-trans x lt1 , ⟪ >-tr< x₂ lt1 , >-tr< x₃ lt1 ⟫ ⟫  tt tt tt (t-left _ _ x x₂ x₃ ti) (t-single _ _)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .leaf .(node key₂ _ _ _))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .(node key₁ _ _ _) .leaf) (node kp ⟪ Red , _ ⟫ leaf _)) .kn .vn (t-node key₁ .kg .kp x x₁ x₂ x₃ x₄ x₅ ti (t-right .kp key₂ x₆ x₇ x₈ ti₁)) (rbr-rotate-rl .leaf .leaf kg kp kn _ lt1 lt2 rbr-leaf) = t-node _ _ _ lt1 lt2 ⟪ <-trans x lt1 , ⟪ >-tr< x₂ lt1 , >-tr< x₃ lt1 ⟫ ⟫  tt tt ⟪ <-trans lt2 x₆ , ⟪ <-tr> x₇ lt2 , <-tr> x₈ lt2 ⟫ ⟫   (t-left _ _ x x₂ x₃ ti) (t-right _ _ x₆ x₇ x₈ ti₁)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) .leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .(node key₁ _ _ _) t₂) (node kp ⟪ Red , _ ⟫ leaf _)) key value (t-node key₁ .kg .kp x x₁ x₂ x₃ x₄ x₅ ti (t-left key₂ .kp x₆ x₇ x₈ ti₁)) (rbr-rotate-rl t₂ .leaf kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti₁ trb
--   ... | t-single .kn .(⟪ Red , vn ⟫) = t-node _ _ _ (proj1 rr00) (proj1 rr01)  ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00) , >-tr< x₃ (proj1 rr00) ⟫ ⟫  tt tt tt (t-left _ _ x x₂ x₃ ti) (t-single _ _) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr01 : (kn < kp) ∧ ⊤ ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--   ... | t-left key₃ .kn {v1} {v3} {t₇} {t₃} x₉ x₁₀ x₁₁ ti₀ = t-node _ _ _ (proj1 rr00) (proj1 rr01) ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00) , >-tr< x₃ (proj1 rr00) ⟫ ⟫ ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫ tt tt (t-node _ _ _  x (proj1 rr02) x₂ x₃ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti ti₀) (t-single _ _) where
--           rr00 : (kg < kn) ∧ ((kg < key₃) ∧ tr> kg t₇ ∧ tr> kg t₃) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₃ < kp) ∧ tr< kp t₇ ∧ tr< kp t₃) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr03 = proj1 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) .(node key₃ _ _ _))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .(node key₁ _ _ _) t₂) (node kp ⟪ Red , _ ⟫ leaf _)) key value (t-node key₁ .kg .kp x x₁ x₂ x₃ x₄ x₅ ti (t-node key₂ .kp key₃ x₆ x₇ x₈ x₉ x₁₀ x₁₁ ti₁ ti₂)) (rbr-rotate-rl t₂ .leaf kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti₁ trb
--   ... | t-single .kn .(⟪ Red , vn ⟫) = t-node _ _ _ (proj1 rr00) (proj1 rr01)  ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00) , >-tr< x₃ (proj1 rr00) ⟫ ⟫  tt tt  ⟪ <-trans (proj1 rr01)  x₇ , ⟪ <-tr> x₁₀ (proj1 rr01)   , <-tr> x₁₁ (proj1 rr01) ⟫ ⟫  (t-left _ _ x x₂ x₃ ti) (t-right _ _ x₇ x₁₀ x₁₁ ti₂) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ⊤ ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₈ , x₉ ⟫ ⟫
--   ... | t-left key₄ .kn {v1} {v3} {t₇} {t₃} x₁₂ x₁₃ x₁₄ ti₀ = t-node _ _ _ (proj1 rr00) (proj1 rr01)  ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00) , >-tr< x₃ (proj1 rr00) ⟫ ⟫  ⟪ x₁₂ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  tt ⟪ <-trans (proj1 rr01) x₇ , ⟪ <-tr> x₁₀ (proj1 rr01) , <-tr> x₁₁ (proj1 rr01) ⟫ ⟫  (t-node _ _ _ x (proj1 rr02) x₂ x₃ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti ti₀) (t-right _ _ x₇  x₁₀ x₁₁ ti₂) where
--           rr00 : (kg < kn) ∧ ((kg < key₄) ∧ tr> kg t₇ ∧ tr> kg t₃) ∧ ⊤
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj1 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₄ < kp) ∧ tr< kp t₇ ∧ tr< kp t₃) ∧ ⊤
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₈ , x₉ ⟫ ⟫
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) .leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf t₂) (node kp ⟪ Red , _ ⟫ (node key₁ value₁ t₃ t₄) _)) key value (t-right .kg .kp x x₁ x₂ (t-left key₂ .kp x₃ x₄ x₅ ti)) (rbr-rotate-rl t₂ .(node key₁ value₁ t₃ t₄) kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-right .kn .key₁ x₆ x₇ x₈ t = t-node _ _ _ (proj1 rr00) (proj1 rr01)  tt tt  ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫  tt  (t-single _ _) (t-left _ _ (proj1 rr03) (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) t) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr02 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ⊤ ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₄ , x₅ ⟫ ⟫
--           rr03 = proj2 (proj2 rr01)
--   ... | t-node key₃ .kn .key₁ {v0} {v1} {v2} {t₇} {t₈} {t₁₀} x₆ x₇ x₈ x₉ x₁₀ x₁₁ t t₁ = t-node _ _ _ (proj1 rr00) (proj1 rr01)  tt ⟪ x₆ , ⟪ x₈ , x₉ ⟫ ⟫  ⟪ x₇ , ⟪ x₁₀   , x₁₁ ⟫ ⟫ tt   (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) t) (t-left _ _ (proj1 rr03) (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) t₁) where
--           rr00 : (kg < kn) ∧ ((kg < key₃) ∧ tr> kg t₇ ∧ tr> kg t₈) ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr02 = proj1 (proj2 rr00)
--           rr04 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₃ < kp) ∧ tr< kp t₇ ∧ tr< kp t₈) ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₄ , x₅ ⟫ ⟫
--           rr03 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₂ _ _ _) .(node key₃ _ _ _))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .leaf t₂) (node kp ⟪ Red , _ ⟫ (node key₁ value₁ t₃ t₄) _)) key value (t-right .kg .kp x x₁ x₂ (t-node key₂ .kp key₃ x₃ x₄ x₅ x₆ x₇ x₈ ti ti₁)) (rbr-rotate-rl t₂ .(node key₁ value₁ t₃ t₄) kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti trb
--   ... | t-right .kn .key₁ x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01)  tt tt  ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₄ , ⟪ <-tr> x₇ (proj1 rr01) , <-tr> x₈ (proj1 rr01)  ⟫ ⟫  (t-single _ _) (t-node _ _ _ (proj1 rr03) x₄ (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) x₇ x₈ t ti₁ ) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr01 : (kn < kp) ∧ ⊤ ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₅ , x₆ ⟫ ⟫
--           rr03 = proj2 (proj2 rr01)
--   ... | t-node key₄ .kn .key₁ {v0} {v1} {v2} {t₇} {t₈} {t₁₀} x₉ x₁₀ x₁₁ x₁₂ x₁₃ x₁₄ t t₁ = t-node _ _ _ (proj1 rr00) (proj1 rr01)  tt ⟪ x₉ , ⟪  x₁₁ , x₁₂ ⟫ ⟫ ⟪ x₁₀ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₄ , ⟪ <-tr> x₇ (proj1 rr01) , <-tr> x₈ (proj1 rr01) ⟫ ⟫  (t-right _ _ (proj1 rr02) (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) t) (t-node _ _ _ (proj1 rr04) x₄ (proj1 (proj2 rr04)) (proj2 (proj2 rr04)) x₇ x₈ t₁ ti₁ ) where
--           rr00 : (kg < kn) ∧ ((kg < key₄) ∧ tr> kg t₇ ∧ tr> kg t₈) ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₁
--           rr02 = proj1 (proj2 rr00)
--           rr05 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₄ < kp) ∧ tr< kp t₇ ∧ tr< kp t₈) ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₃ , ⟪ x₅ , x₆ ⟫ ⟫
--           rr03 = proj1 (proj2 rr01)
--           rr04 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₃ _ _ _) .leaf)) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .(node key₂ _ _ _) t₂) (node kp ⟪ Red , _ ⟫ (node key₁ value₁ t₃ t₄) _)) key value (t-node key₂ .kg .kp x x₁ x₂ x₃ x₄ x₅ ti (t-left key₃ .kp x₆ x₇ x₈ ti₁)) (rbr-rotate-rl t₂ .(node key₁ value₁ t₃ t₄) kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti₁ trb
--   ... | t-right .kn .key₁ x₉ x₁₀ x₁₁ t = t-node _ _ _ (proj1 rr00) (proj1 rr01)  ⟪ <-trans x (proj1 rr00)  , ⟪ >-tr< x₂ (proj1 rr00)  , >-tr< x₃ (proj1 rr00) ⟫ ⟫ tt  ⟪ x₉ , ⟪ x₁₀ , x₁₁ ⟫ ⟫  tt  (t-left _ _ x  x₂ x₃ ti ) (t-left _ _ (proj1 rr03) (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) t) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ⊤ ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr03 = proj2 (proj2 rr01)
--   ... | t-node key₄ .kn .key₁ {v0} {v1} {v2} {t₇} {t₈} {t₁₀} x₉ x₁₀ x₁₁ x₁₂ x₁₃ x₁₄ t t₁ = t-node _ _ _ (proj1 rr00) (proj1 rr01)  ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00) , >-tr< x₃ (proj1 rr00) ⟫ ⟫  ⟪ x₉ , ⟪ x₁₁ , x₁₂ ⟫ ⟫  ⟪ x₁₀ , ⟪ x₁₃ , x₁₄ ⟫ ⟫  tt (t-node _ _ _ x (proj1 rr02) x₂ x₃ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti t) (t-left _ _ (proj1 rr04) (proj1 (proj2 rr04)) (proj2 (proj2 rr04)) t₁) where
--           rr00 : (kg < kn) ∧ ((kg < key₄) ∧ tr> kg t₇ ∧ tr> kg t₈) ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj1 (proj2 rr00)
--           rr05 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₄ < kp) ∧ tr< kp t₇ ∧ tr< kp t₈) ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₇ , x₈ ⟫ ⟫
--           rr03 = proj1 (proj2 rr01)
--           rr04 = proj2 (proj2 rr01)
--   RB-repl→ti (node kg ⟪ Black , vg ⟫ _ (node kp ⟪ Red , vp ⟫ .(node key₃ _ _ _) .(node key₄ _ _ _))) (node kn ⟪ Black , vn ⟫ (node kg ⟪ Red , _ ⟫ .(node key₂ _ _ _) t₂) (node kp ⟪ Red , _ ⟫ (node key₁ value₁ t₃ t₄) _)) key value (t-node key₂ .kg .kp x x₁ x₂ x₃ x₄ x₅ ti (t-node key₃ .kp key₄ x₆ x₇ x₈ x₉ x₁₀ x₁₁ ti₁ ti₂)) (rbr-rotate-rl t₂ .(node key₁ value₁ t₃ t₄) kg kp kn _ lt1 lt2 trb) with RB-repl→ti _ _ _ _ ti₁ trb
--   ... | t-right .kn .key₁ x₁₂ x₁₃ x₁₄ t = t-node _ _ _ (proj1 rr00) (proj1 rr01)   ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00) , >-tr< x₃ (proj1 rr00) ⟫ ⟫ tt  ⟪  x₁₂  , ⟪  x₁₃  , x₁₄  ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₇ , ⟪ <-tr> x₁₀ (proj1 rr01) , <-tr> x₁₁ (proj1 rr01) ⟫ ⟫  (t-left _ _ x x₂ x₃ ti) (t-node _ _ _ (proj1 rr03) x₇ (proj1 (proj2 rr03)) (proj2 (proj2 rr03)) x₁₀ x₁₁ t ti₂ ) where
--           rr00 : (kg < kn) ∧ ⊤ ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ⊤ ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₈ , x₉ ⟫ ⟫
--           rr03 = proj2 (proj2 rr01)
--   ... | t-node key₅ .kn .key₁ {v0} {v1} {v2} {t₇} {t₈} {t₁₀} x₁₂ x₁₃ x₁₄ x₁₅ x₁₆ x₁₇ t t₁ = t-node _ _ _ (proj1 rr00) (proj1 rr01)  ⟪ <-trans x (proj1 rr00) , ⟪ >-tr< x₂ (proj1 rr00)  , >-tr< x₃ (proj1 rr00) ⟫ ⟫  ⟪ x₁₂ , ⟪ x₁₄ , x₁₅ ⟫ ⟫  ⟪ x₁₃ , ⟪ x₁₆ , x₁₇ ⟫ ⟫  ⟪ <-trans (proj1 rr01) x₇  , ⟪ <-tr> x₁₀ (proj1 rr01) , <-tr> x₁₁ (proj1 rr01) ⟫ ⟫   (t-node _ _ _ x (proj1 rr02) x₂  x₃ (proj1 (proj2 rr02)) (proj2 (proj2 rr02)) ti t ) (t-node _ _ _ (proj1 rr04) x₇ (proj1 (proj2 rr04)) (proj2 (proj2 rr04)) x₁₀ x₁₁ t₁ ti₂ ) where
--           rr00 : (kg < kn) ∧ ((kg < key₅) ∧ tr> kg t₇ ∧ tr> kg t₈) ∧ ((kg < key₁) ∧ tr> kg t₃ ∧ tr> kg t₄)
--           rr00 = RB-repl→ti> _ _ _ _ _ trb lt1 x₄
--           rr02 = proj1 (proj2 rr00)
--           rr05 = proj2 (proj2 rr00)
--           rr01 : (kn < kp) ∧ ((key₅ < kp) ∧ tr< kp t₇ ∧ tr< kp t₈) ∧ ((key₁ < kp) ∧ tr< kp t₃ ∧ tr< kp t₄)
--           rr01 = RB-repl→ti< _ _ _ _ _ trb lt2 ⟪ x₆ , ⟪ x₈ , x₉ ⟫ ⟫
--           rr03 = proj1 (proj2 rr01)
--           rr04 = proj2 (proj2 rr01)


--
-- 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 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  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  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  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 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 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 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 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 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 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 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 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 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) → (tree orig : bt A )
           →  (stack : List (bt A)) → (pg : PG A 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 () ) ⟫


stackCase2 : {n : Level} {A : Set n} → (rest : List ( bt (Color ∧ A)))
           → ( tree parent grand orig : bt (Color ∧ A)) →  (key : ℕ)
           → stackInvariant key tree  orig ( tree ∷ parent ∷ grand ∷ rest )
           → stackInvariant key grand orig (grand ∷ rest )
stackCase2 rest tree parent grand orig key (s-right .tree .orig tree₁ x si) = sc01 sc00 where
     sc00 : stackInvariant key parent orig (parent ∷ grand ∷ rest )
     sc00 with si-property1 si
     ... | refl = si
     sc01 : stackInvariant key parent orig (parent ∷ grand ∷ rest ) → stackInvariant key grand orig (grand ∷ rest )
     sc01 (s-right .parent .orig tree₁ x si2) with si-property1 si2
     ... | refl = si2
     sc01 (s-left .parent .orig tree x si2) with si-property1 si2
     ... | refl = si2
stackCase2 rest tree parent grand orig key (s-left .tree .orig tree₁ x si) = sc01 sc00 where
     sc00 : stackInvariant key parent orig (parent ∷ grand ∷ rest )
     sc00 with si-property1 si
     ... | refl = si
     sc01 : stackInvariant key parent orig (parent ∷ grand ∷ rest ) → stackInvariant key grand orig (grand ∷ rest )
     sc01 (s-right .parent .orig tree₁ x si2) with si-property1 si2
     ... | refl = si2
     sc01 (s-left .parent .orig tree x si2) with si-property1 si2
     ... | refl = si2

stackCase3 : {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 
stackCase3 .[] tree .tree key ti s-nil = ti
stackCase3 .(node _ _ leaf leaf ∷ []) .leaf .(node _ _ leaf leaf) key (t-single _ _) (s-right .leaf .(node _ _ leaf leaf) .leaf x s-nil) = t-leaf
stackCase3 .(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
stackCase3 .(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
stackCase3 .(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
stackCase3 .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-right .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) with stackCase3 _ _ _ _ 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
stackCase3 .(node _ _ tree₁ tree ∷ _) tree orig key ti (s-right .tree .orig tree₁ x si2@(s-left .(node _ _ tree₁ tree) .orig tree₂ x₁ si)) = ?
stackCase3 rest tree orig key ti (s-left .tree .orig tree₁ x si) = ?

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

-- this is too complacted to extend all arguments at once
--
-- RBTtoRBI  : {n : Level} {A : Set n}  → (tree repl : bt (Color ∧ A)) → (key : ℕ) → (value : A) → RBtreeInvariant tree
--      → replacedRBTree key value tree repl → RBtreeInvariant repl
-- RBTtoRBI {_} {A} tree repl key value rbi rlt = ?
--
-- create RBT invariant after findRBT, continue to replaceRBT
--
replaceRBTNode : {n m : Level} {A : Set n } {t : Set m }
 → (key : ℕ) (value : A)
 → (tree0 : bt (Color ∧ A))
 → RBtreeInvariant tree0
 → (tree1 : bt (Color ∧ A))
 → (stack : List (bt (Color ∧ A)))
 → RBtreeInvariant tree1 ∧ stackInvariant key tree1 tree0 stack
 → (exit : (r : RBI key value tree0 tree1 stack ) → (tree1 ≡ leaf ) ∨ ( node-key tree1 ≡ just key )) → t
replaceRBTNode key value tree0 rbi tree1 stack rbi-stack exit = {!!}

--
-- RBT is blanced with the stack, simply rebuild tree without rototation
--
rebuildRBT : {n m : Level} {A : Set n} {t : Set m}
     → (key : ℕ) → (value : A)
     → (orig repl : bt (Color ∧ A))
     → (stack : List (bt (Color ∧ A)))
     → (r : RBI key value orig repl stack )
     → black-depth repl  ≡ black-depth (child-replaced key (RBI.tree r))
     → (next : (repl1 : (bt (Color ∧ A))) →  (stack1 : List (bt (Color ∧ A)))
        → (r : RBI key value orig repl1 stack1 )
        → length stack1 < length stack  → t )
     → (exit : (repl : bt (Color ∧ A) ) → (stack1 : List (bt (Color ∧ A)))
        →  stack1 ≡ (orig ∷ [])
        →  RBI key value orig repl stack1
        → t ) → t
rebuildRBT key value orig repl stack r bdepth-eq next exit = {!!}

insertCase5 : {n m : Level} {A : Set n} {t : Set m}
     → (key : ℕ) → (value : A)
     → (orig tree : bt (Color ∧ A))
     → (stack : List (bt (Color ∧ A)))
     → (r : RBI key value orig tree stack )
     → (pg : PG (Color ∧ A) tree stack)
     → color (PG.uncle pg) ≡ Black → color (PG.parent pg) ≡ Red
     → (next : (tree1 : (bt (Color ∧ A))) →  (stack1 : List (bt (Color ∧ A)))
        → (r : RBI key value orig tree1 stack1 )
        → length stack1 < length stack  → t ) → t
insertCase5 {n} {m} {A} {t} key value orig tree stack r pg cu=b cp=r next = insertCase51 tree (PG.grand pg) refl refl where
    -- check inner repl case
    --     node-key parent < node-key repl < node-key grand  → rotateLeft  parent    then insertCase6
    --     node-key grand  < node-key repl < node-key parent → rotateRight parent    then insertCase6
    --     else insertCase6
    insertCase51 : (tree1 grand : bt (Color ∧ A)) → tree1 ≡ tree → grand ≡ PG.grand pg → t
    insertCase51 leaf grand teq geq = next {!!} {!!} {!!} {!!}
    insertCase51 (node kr vr rleft rright) leaf teq geq = {!!}    -- can't happen
    insertCase51 (node kr vr rleft rright) (node kg vg grand grand₁) teq geq with <-cmp kr kg
    ... | tri< a ¬b ¬c = insertCase511 (PG.parent pg) refl where
          insertCase511 : (parent : bt (Color ∧ A)) → parent ≡ PG.parent pg → t
          insertCase511 leaf peq = ⊥-elim (proj2 (pg-prop-1 _ tree orig stack pg) (sym peq) )
          insertCase511 (node key₂ ⟪ co , value ⟫ n1 n2) peq with <-cmp key key₂
          ... | tri< a ¬b ¬c = next {!!} {!!} {!!} {!!}
          ... | tri≈ ¬a b ¬c = {!!} -- can't happen
          ... | tri> ¬a ¬b c = next {!!} {!!} {!!} {!!} --- rotareRight → insertCase6 key value orig ? stack ? pg next exit
    ... | tri≈ ¬a b ¬c = {!!} -- can't happen
    ... | tri> ¬a ¬b c = {!!} where
          insertCase511 : (parent : bt (Color ∧ A)) → parent ≡ PG.parent pg → t
          insertCase511 leaf peq = ⊥-elim (proj2 (pg-prop-1 _ tree orig stack pg) (sym peq) )
          insertCase511 (node key₂ ⟪ co , value ⟫ n1 n2) peq with <-cmp key key₂
          ... | tri< a ¬b ¬c = next {!!} {!!} {!!} {!!} --- rotareLeft → insertCase6 key value orig ? stack ? pg next exit
          ... | tri≈ ¬a b ¬c = {!!} -- can't happen
          ... | tri> ¬a ¬b c = next {!!} {!!} {!!} {!!}

--
-- replaced node increase blackdepth, so we need tree rotate
--
-- case2 tree is Red
--
--   go upward until
--
--   if root
--       insert top
--   if unkle is leaf or Black
--       go insertCase5/6
--
--   make color tree ≡ Black , color unkle ≡ Black, color grand ≡ Red
--   loop with grand as repl
--
-- case5/case6 rotation
--
--   rotate and rebuild replaceTree and rb-invariant


replaceRBP : {n m : Level} {A : Set n} {t : Set m}
     → (key : ℕ) → (value : A)
     → (orig repl : bt (Color ∧ A))
     → (stack : List (bt (Color ∧ A)))
     → (r : RBI key value orig repl stack )
     → (next : (repl1 : (bt (Color ∧ A))) →  (stack1 : List (bt (Color ∧ A)))
        → (r : RBI key value orig repl1 stack1 )
        → length stack1 < length stack  → t )
     → (exit : (repl : bt (Color ∧ A) ) → (stack1 : List (bt (Color ∧ A)))
        →  stack1 ≡ (orig ∷ [])
        →  RBI key value orig repl stack1
        → t ) → t
replaceRBP {n} {m} {A} {t} key value orig repl stack r next exit with RBI.state r
... | rebuild bdepth-eq rot = rebuildRBT key value orig repl stack r bdepth-eq next exit
... | top-black eq rot = {!!}
... | rotate repl-red pdepth< rot with stackToPG (RBI.tree r) orig stack (RBI.si r)
... | case1 eq  = exit repl stack eq r     -- no stack, replace top node
... | case2 (case1 eq) = insertCase12 orig refl (RBI.si r)  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
    rb01 : stackInvariant key (RBI.tree r) orig stack
    rb01 = RBI.si r
    insertCase12 :  (tr0 : bt (Color ∧ A)) → tr0 ≡ orig
       → stackInvariant key (RBI.tree r) orig stack
       → t
    insertCase12 leaf eq1 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
    insertCase12  tr0@(node key₁ value₁ left right) refl si with <-cmp key key₁ | child-replaced key (node key₁ value₁ left right) in creq
    ... | tri< a ¬b ¬c | cr = exit (to-black (node key₁ value₁ repl right)) (orig ∷ []) refl record {
         tree = orig
         ; 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 (rbr-black-left repl-red a (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot))
         } 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  )
       rb05 : child-replaced key (node key₁ value₁ left right) ≡ left
       rb05 with <-cmp key key₁
       ... | tri< a ¬b ¬c = refl
       ... | tri≈ ¬a b ¬c = ⊥-elim (¬a a)
       ... | tri> ¬a ¬b c = ⊥-elim (¬a a)
       rb06 : black-depth repl ≡ black-depth right
       rb06 = begin
         black-depth repl ≡⟨ sym (RB-repl→eq _ _ (RBI.treerb r) rot) ⟩
         black-depth (RBI.tree r) ≡⟨ cong black-depth (sym (rb04 si eq refl)) ⟩
         black-depth left ≡⟨ (RBtreeEQ (RBI.origrb r)) ⟩
         black-depth right ∎
            where open ≡-Reasoning
    ... | tri≈ ¬a b ¬c | cr = ⊥-elim ( rb06 _ eq (RBI.si r) b ) where -- can't happen
       rb06 : (stack    : List (bt (Color ∧ A))) → stack ≡ RBI.tree r ∷ node key₁ value₁ left right ∷ []
         →  stackInvariant key (RBI.tree r) (node key₁ value₁ left right) stack
         → key ≡ key₁
         → ⊥
       rb06 (.right ∷ node key₁ value₁ left right ∷ []) refl (s-right .right .(node key₁ value₁ left right) .left x s-nil) eq = ⊥-elim ( nat-≡< (sym eq) x)
       rb06 (.left ∷ node key₁ value₁ left right ∷ []) refl (s-left .left .(node key₁ value₁ left right) .right x s-nil) eq = ⊥-elim ( nat-≡< eq x)
    ... | tri> ¬a ¬b c | cr = exit (to-black (node key₁ value₁ left repl)) (orig ∷ [])  refl record {
         tree = orig
         ; 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 (rbr-black-right repl-red c (subst (λ k → replacedRBTree key value k repl) (sym (rb04 si eq refl)) rot))
         } 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  )
       rb05 : child-replaced key (node key₁ value₁ left right) ≡ right
       rb05 with <-cmp key key₁
       ... | tri< a ¬b ¬c = ⊥-elim (¬c c)
       ... | tri≈ ¬a b ¬c = ⊥-elim (¬c c)
       ... | tri> ¬a ¬b c = refl
       rb06 : black-depth repl ≡ black-depth left
       rb06 = begin
         black-depth repl ≡⟨ sym (RB-repl→eq _ _ (RBI.treerb r) rot) ⟩
         black-depth (RBI.tree r) ≡⟨ cong black-depth (sym (rb04 si eq refl)) ⟩
         black-depth right ≡⟨ (sym (RBtreeEQ (RBI.origrb r))) ⟩
         black-depth left ∎
            where open ≡-Reasoning  
... | case2 (case2 pg) with (PG.parent pg) in preq
... | leaf = {!!} -- can't happen
... | node kp ⟪ Black , vp₁ ⟫ t₁ t₂ = ?  -- insertCase1 -- parent is Black 
... | node kp ⟪ Red , vp₁ ⟫ t₁₁ t₁₂ with PG.uncle pg in uneq
... | leaf = {!!} -- insertCase5
... | node key₁ ⟪ Black , value₁ ⟫ t₁ t₂ = {!!} -- insertCase5
... | node key₁ ⟪ Red , value₁ ⟫ t₁ t₂ with PG.pg pg
... | s2-s1p2 {kp} {kg} {vp} {vg} {n1} {n2} x x₁ = next (to-red (node kg vg (to-black (node kp vp repl n1)) (to-black (PG.uncle pg)))) (PG.grand pg ∷ (PG.rest pg))
    record {
         tree = PG.grand pg
         ; origti = RBI.origti r
         ; origrb = RBI.origrb r
         ; treerb = rb01
         ; replrb = rb-red _ _ refl (RBtreeToBlackColor _ rb02) ? (rb-black _ _ ? (RBI.replrb r) rb04) (RBtreeToBlack _ rb02)
         ; si = stackCase2 (PG.rest pg) (RBI.tree r) (PG.parent pg) (PG.grand pg) orig _  rb00
         ; state = rotate refl ? (subst₂ (λ j k → replacedRBTree key value j k ) (sym ?) refl  (rbr-flip-ll repl-red (rb05 refl uneq) ? rot))
     }  ? 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) _ (stackCase2 (PG.rest pg) (RBI.tree r) (PG.parent pg) (PG.grand pg) orig _  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
       rb06 : key < kp
       rb06 = si-property-< ? ? ?
... | s2-1sp2 {kp} {kg} {vp} {vg} {n1} {n2} x x₁ = {!!}
... | s2-s12p {kp} {kg} {vp} {vg} {n1} {n2} x x₁ = {!!}
... | s2-1s2p {kp} {kg} {vp} {vg} {n1} {n2} x x₁ = {!!}