changeset 655:b602e3f070df

UChain rewrite
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Fri, 01 Jul 2022 14:36:38 +0900
parents 6df8b836e983
children db9477c80dce
files src/zorn.agda
diffstat 1 files changed, 74 insertions(+), 60 deletions(-) [+]
line wrap: on
line diff
--- a/src/zorn.agda	Thu Jun 30 10:40:24 2022 +0900
+++ b/src/zorn.agda	Fri Jul 01 14:36:38 2022 +0900
@@ -233,17 +233,39 @@
    field
       x<sup : {y : Ordinal} → odef B y → (y ≡ x ) ∨ (y << x )
 
-record ZChain1 ( z : Ordinal ) : Set (Level.suc n) where
+record UChain (chain : Ordinal → HOD) (x : Ordinal) (z : Ordinal) : Set n where 
+   -- Union of supf z which o< x
    field
-      supf : Ordinal → HOD
-      chain-mono : {x : Ordinal} → x o≤ z → supf x ⊆' supf z 
+      u : Ordinal
+      u<x : u o< x
+      chain∋z : odef (chain u) z
 
-ZChain0 : (A : HOD ) → Set (Level.suc n)
-ZChain0 A = ZChain1 ( & A )
+Chain-uniq : (A : HOD ) ( f : Ordinal → Ordinal ) → {y : Ordinal} (ay : odef A y) → (x : Ordinal)
+     → ( Ordinal → HOD ) → Set (Level.suc n)
+Chain-uniq A f {y} ay x chain  with Oprev-p x
+... | yes op = st1 where
+      px = Oprev.oprev op
+      st1 : Set (Level.suc n)
+      st1 with ODC.∋-p O A (* x)
+      ... | no noax = chain x ≡ chain px
+      ... | yes ax with ODC.p∨¬p O ( HasPrev A (chain px) ax f )   
+      ... | case1 pr = chain x ≡ chain px
+      ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A (chain px) ax )
+      ... | case1 is-sup = chain x ≡ schain where
+            schain : HOD
+            schain = record { od = record { def = λ x → odef (chain px) x ∨ (FClosure A f y x) } ; odmax = & A ; <odmax = λ {y} sy → {!!}  }
+      ... | case2 ¬x=sup = chain x ≡ chain px
+... | no ¬ox = chain x ≡ record { od = record { def = λ z → odef A z ∧ ( UChain chain z x ∨ FClosure A f y z ) ; odmax = & A ; <odmax = λ {y} sy → {!!}  } }
 
-record ZChain ( A : HOD )  (init : Ordinal)  ( f : Ordinal → Ordinal ) (zc0 : ZChain0 A ) ( z : Ordinal ) : Set (Level.suc n) where
+record ZChain1 ( A : HOD )    ( f : Ordinal → Ordinal ) {y : Ordinal } (ay : odef A y ) ( z : Ordinal ) : Set (Level.suc n) where
+   field
+      chain : Ordinal → HOD
+      chain-mono : {x : Ordinal} → x o≤ z → chain x ⊆' chain z 
+      chain-uniq : Chain-uniq A f ay z chain
+
+record ZChain ( A : HOD )    ( f : Ordinal → Ordinal ) {init : Ordinal} (ay : odef A init)  (zc0 : ZChain1 A f ay (& A) ) ( z : Ordinal ) : Set (Level.suc n) where
    chain : HOD
-   chain = ZChain1.supf zc0 z 
+   chain = ZChain1.chain zc0 z 
    field
       chain⊆A : chain ⊆' A
       chain∋init : odef chain init
@@ -254,14 +276,6 @@
           → HasPrev A chain ab f ∨  IsSup A chain ab  
           → * a < * b  → odef chain b
 
-record UZFChain ( A : HOD )  ( f : Ordinal → Ordinal ) (zc0 : ZChain0 A ) (x y  : Ordinal) 
-         (prev : (z : Ordinal) → z o< x → ZChain A y f zc0 z) (z : Ordinal) : Set n where 
-   -- Union of ZFChain from y which has maximality o< x
-   field
-      u : Ordinal
-      u<x : u o< x
-      chain∋z : odef (ZChain.chain (prev u u<x  )) z
-
 record Maximal ( A : HOD )  : Set (Level.suc n) where
    field
       maximal : HOD
@@ -333,7 +347,7 @@
      cf-is-≤-monotonic : (nmx : ¬ Maximal A ) →  ≤-monotonic-f A ( cf nmx )
      cf-is-≤-monotonic nmx x ax = ⟪ case2 (proj1 ( cf-is-<-monotonic nmx x ax  ))  , proj2 ( cf-is-<-monotonic nmx x ax  ) ⟫
 
-     sp0 : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) (zc0 : ZChain0 A) (zc : ZChain A (& s) f zc0 (& A) ) 
+     sp0 : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) (zc0 : ZChain1 A f as0 (& A) ) (zc : ZChain A f as0 zc0 (& A) ) 
         (total : IsTotalOrderSet (ZChain.chain zc) )  → SUP A (ZChain.chain zc)
      sp0 f mf zc0 zc total = supP (ZChain.chain zc) (ZChain.chain⊆A zc) total 
      zc< : {x y z : Ordinal} → {P : Set n} → (x o< y → P) → x o< z → z o< y → P
@@ -342,7 +356,7 @@
      ---
      --- the maximum chain  has fix point of any ≤-monotonic function
      ---
-     fixpoint :  ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) (zc0 : ZChain0 A ) (zc : ZChain A (& s) f zc0 (& A) )
+     fixpoint :  ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) (zc0 : ZChain1 A f as0 (& A)) (zc : ZChain A f as0 zc0 (& A) )
             → (total : IsTotalOrderSet (ZChain.chain zc) )
             → f (& (SUP.sup (sp0 f mf zc0 zc total ))) ≡ & (SUP.sup (sp0 f mf zc0 zc  total))
      fixpoint f mf zc0 zc total = z14 where
@@ -391,7 +405,7 @@
      -- ZChain forces fix point on any ≤-monotonic function (fixpoint)
      -- ¬ Maximal create cf which is a <-monotonic function by axiom of choice. This contradicts fix point of ZChain
      --
-     z04 :  (nmx : ¬ Maximal A ) → (zc0 : ZChain0 A) (zc : ZChain A (& s) (cf nmx) zc0 (& A)) → IsTotalOrderSet (ZChain.chain zc) → ⊥
+     z04 :  (nmx : ¬ Maximal A ) → (zc0 : ZChain1 A (cf nmx) as0 (& A)) (zc : ZChain A (cf nmx) as0 zc0 (& A)) → IsTotalOrderSet (ZChain.chain zc) → ⊥
      z04 nmx zc0 zc total = <-irr0  {* (cf nmx c)} {* c} (subst (λ k → odef A k ) (sym &iso) (proj1 (is-cf nmx (SUP.A∋maximal  sp1 ))))
                                                (subst (λ k → odef A (& k)) (sym *iso) (SUP.A∋maximal sp1) )
            (case1 ( cong (*)( fixpoint (cf nmx) (cf-is-≤-monotonic nmx ) zc0 zc total ))) -- x ≡ f x ̄
@@ -405,50 +419,52 @@
      --
 
      sind : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) → (x : Ordinal)
-         → ((z : Ordinal) → z o< x → ZChain1 z ) → ZChain1 x
+         → ((z : Ordinal) → z o< x → ZChain1 A f ay z ) → ZChain1 A f ay x
      sind f mf {y} ay x prev  with Oprev-p x
      ... | yes op = sc4 where
           open ZChain1
           px = Oprev.oprev op
-          sc : ZChain1 px
+          sc : ZChain1 A f ay px
           sc = prev px (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc ) 
-          no-ext : ZChain1 x
-          no-ext = record { supf = s01 ; chain-mono = ? } where
+          no-ext : ZChain1 A f ay x
+          no-ext = record { chain = s01 ; chain-mono = ? ; chain-uniq = ? } where
                 s01 : Ordinal → HOD
-                s01 z = supf (prev px (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc )) z
+                s01 z = chain (prev px (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc )) z
 
-          sc4 : ZChain1 x
+          sc4 : ZChain1 A f ay x
           sc4 with ODC.∋-p O A (* x)
           ... | no noax = {!!}
-          ... | yes ax with ODC.p∨¬p O ( HasPrev A (ZChain1.supf sc x) ax f )   
+          ... | yes ax with ODC.p∨¬p O ( HasPrev A (ZChain1.chain sc x) ax f )   
           ... | case1 pr = {!!}
-          ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A (ZChain1.supf sc x) ax )
+          ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A (ZChain1.chain sc x) ax )
           ... | case1 is-sup = {!!} where
                 -- A∋sc -- x is a sup of zc 
-                sup0 : SUP A (ZChain1.supf sc x )
+                sup0 : SUP A (ZChain1.chain sc x )
                 sup0 = record { sup = * x ; A∋maximal = ax ; x<sup = x21 } where
-                        x21 :  {y : HOD} → (ZChain1.supf sc x) ∋ y → (y ≡ * x) ∨ (y < * x)
+                        x21 :  {y : HOD} → (ZChain1.chain sc x) ∋ y → (y ≡ * x) ∨ (y < * x)
                         x21 {y} zy with IsSup.x<sup is-sup zy 
                         ... | case1 y=x = case1 (subst₂ (λ j k → j ≡ * k ) *iso &iso ( cong (*) y=x)  )
                         ... | case2 y<x = case2 (subst₂ (λ j k → j < * k ) *iso &iso y<x  )
                 sp : HOD
                 sp = SUP.sup sup0 
                 schain : HOD
-                schain = record { od = record { def = λ x → odef (ZChain1.supf sc x) x ∨ (FClosure A f (& sp) x) } ; odmax = & A ; <odmax = λ {y} sy → {!!}  }
+                schain = record { od = record { def = λ x → odef (ZChain1.chain sc x) x ∨ (FClosure A f (& sp) x) } ; odmax = & A ; <odmax = λ {y} sy → {!!}  }
           ... | case2 ¬x=sup = {!!}
-     ... | no ¬ox = {!!} 
+     ... | no ¬ox = ? where
+          sc5 : HOD
+          sc5 = record { od = record { def = λ z → odef A z ∧ UChain ? x z } ; odmax = & A ; <odmax = λ {y} sy → {!!}  }
 
-     ind : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) → (zc0 : ZChain0 A) → (x : Ordinal)
-         → ((z : Ordinal) → z o< x → ZChain A y f zc0 z) → ZChain A y f zc0 x
-     ind f mf {y} ay zc0 x prev with Oprev-p x
+     ind : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) → (x : Ordinal) → (zc0 : ZChain1 A f ay (& A)) 
+         → ((z : Ordinal) → z o< x → ZChain A f ay zc0 z) → ZChain A f ay zc0 x
+     ind f mf {y} ay x zc0 prev with Oprev-p x
      ... | yes op = zc4 where
           --
           -- we have previous ordinal to use induction
           --
           px = Oprev.oprev op
           supf : Ordinal → HOD
-          supf = ZChain1.supf zc0
-          zc : ZChain A y f zc0 (Oprev.oprev op)
+          supf = ZChain1.chain zc0
+          zc : ZChain A f ay zc0 (Oprev.oprev op)
           zc = prev px (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc ) 
           zc-b<x : (b : Ordinal ) → b o< x → b o< osuc px
           zc-b<x b lt = subst (λ k → b o< k ) (sym (Oprev.oprev=x op)) lt 
@@ -459,7 +475,7 @@
           --
           no-extenion : ( {a b : Ordinal} → odef (ZChain.chain zc) a → b o< osuc x → (ab : odef A b) →
                     HasPrev A (ZChain.chain zc) ab f ∨  IsSup A (ZChain.chain zc) ab →
-                            * a < * b → odef (ZChain.chain zc) b ) → ZChain A y f zc0 x
+                            * a < * b → odef (ZChain.chain zc) b ) → ZChain A f ay ?  x
           no-extenion is-max = record { chain⊆A = ? -- subst (λ k → k ⊆' A ) {!!} (ZChain.chain⊆A zc)
                      ; initial = subst (λ k →  {y₁ : Ordinal} → odef k y₁ → * y ≤ * y₁ ) {!!} (ZChain.initial zc)
                      ; f-next =  subst (λ k → {a : Ordinal} → odef k a → odef k (f a) ) {!!} (ZChain.f-next zc) 
@@ -483,7 +499,7 @@
                 ... | tri≈ ¬a b₁ ¬c = ⊥-elim (¬a  b<x )
                 ... | tri> ¬a ¬b c  = ⊥-elim (¬a  b<x )
 
-          zc4 : ZChain A y f zc0 x 
+          zc4 : ZChain A f ay zc0 x 
           zc4 with ODC.∋-p O A (* x)
           ... | no noax = no-extenion zc1  where -- ¬ A ∋ p, just skip
                 zc1 : {a b : Ordinal} → odef (ZChain.chain zc) a → b o< osuc x → (ab : odef A b) →
@@ -615,26 +631,24 @@
      ... | no ¬ox = record { chain⊆A = {!!} ; f-next = {!!} ; f-total = ?
                      ; initial = {!!} ; chain∋init  = {!!} ; is-max = {!!} }   where --- limit ordinal case
          supf : Ordinal → HOD
-         supf = ZChain1.supf zc0
-         Uz⊆A : {z : Ordinal} → UZFChain A f zc0 x y prev z ∨ FClosure A f y z → odef A z
-         Uz⊆A {z} (case1 u) = ZChain.chain⊆A ( prev (UZFChain.u u) (UZFChain.u<x u) ) (UZFChain.chain∋z u)
-         Uz⊆A (case2 lt) = A∋fc _ f mf lt 
-         uzc : {z : Ordinal} → (u : UZFChain A f zc0 x y prev z) → ZChain A y f zc0 (UZFChain.u u)
-         uzc {z} u =  prev (UZFChain.u u) (UZFChain.u<x u) 
+         supf = ZChain1.chain zc0
+         uzc : {z : Ordinal} → (u : UChain supf x z) → ZChain A f ay zc0 (UChain.u u)
+         uzc {z} u =  prev (UChain.u u) (UChain.u<x u) 
          Uz : HOD
-         Uz = record { od = record { def = λ z → UZFChain A f zc0 x y prev z ∨ FClosure A f y z } ; odmax = & A
-             ; <odmax = λ lt → subst (λ k → k o< & A ) &iso (c<→o< (subst (λ k → odef A k ) (sym &iso) (Uz⊆A lt))) }
+         Uz = record { od = record { def = λ z → odef A z ∧ ( UChain supf z x ∨ FClosure A f y z ) } ; odmax = & A ; <odmax = ?  }
          u-next : {z : Ordinal} → odef Uz z → odef Uz (f z)
-         u-next {z} (case1 u) = case1 record { u = UZFChain.u u ; u<x = UZFChain.u<x u ; chain∋z = ZChain.f-next ( uzc u ) (UZFChain.chain∋z u)  }
-         u-next {z} (case2 u) = case2 ( fsuc _ u )
+         u-next {z} = ?
+         -- (case1 u) = case1 record { u = UChain.u u ; u<x = UChain.u<x u ; chain∋z = ZChain.f-next ( uzc u ) (UChain.chain∋z u)  }
+         -- u-next {z} (case2 u) = case2 ( fsuc _ u )
          u-initial :  {z : Ordinal} → odef Uz z → * y ≤ * z 
-         u-initial {z} (case1 u) = ZChain.initial ( uzc u )  (UZFChain.chain∋z u)
-         u-initial {z} (case2 u) = s≤fc _ f mf u
+         u-initial {z} = ?
+         -- (case1 u) = ZChain.initial ( uzc u )  (UChain.chain∋z u)
+         -- u-initial {z} (case2 u) = s≤fc _ f mf u
          u-chain∋init :  odef Uz y
-         u-chain∋init = case2 ( init ay )
+         u-chain∋init = ? -- case2 ( init ay )
          supf0 : Ordinal → HOD
          supf0 z with trio< z x
-         ... | tri< a ¬b ¬c = ZChain1.supf zc0 z
+         ... | tri< a ¬b ¬c = ZChain1.chain zc0 z
          ... | tri≈ ¬a b ¬c = Uz 
          ... | tri> ¬a ¬b c = Uz
          u-mono :  {z : Ordinal} {w : Ordinal} → z o≤ w → w o≤ x → supf0 z ⊆' supf0 w
@@ -646,9 +660,9 @@
          ... | tri< a ¬b ¬c = ⊥-elim ( ¬b refl )
          ... | tri≈ ¬a b ¬c = refl
          ... | tri> ¬a ¬b c = refl
-         seq<x : {b : Ordinal } → (b<x : b o< x ) →  ZChain1.supf zc0 b  ≡ supf0 b
+         seq<x : {b : Ordinal } → (b<x : b o< x ) →  ZChain1.chain zc0 b  ≡ supf0 b
          seq<x {b} b<x with trio< b x
-         ... | tri< a ¬b ¬c = cong (λ k → ZChain1.supf zc0 b) o<-irr --  b<x ≡ a
+         ... | tri< a ¬b ¬c = cong (λ k → ZChain1.chain zc0 b) o<-irr --  b<x ≡ a
          ... | tri≈ ¬a b₁ ¬c = ⊥-elim (¬a  b<x )
          ... | tri> ¬a ¬b c  = ⊥-elim (¬a  b<x )
          ord≤< : {x y z : Ordinal} → x o< z → z o≤ y → x o< y
@@ -656,11 +670,11 @@
          ... | case1 z=y  = subst (λ k → x o< k ) z=y x<z
          ... | case2 z<y  = ordtrans x<z z<y
          
-     SZ0 : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) → {y : Ordinal} (ya : odef A y) → ZChain0 A 
-     SZ0 f mf ay = TransFinite {λ z → ZChain1 z} (sind f mf ay ) (& A)
+     SZ0 : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) → {y : Ordinal} (ay : odef A y) → ZChain1 A f ay (& A)
+     SZ0 f mf ay = TransFinite {λ z → ZChain1 A f ay z} (sind f mf ay ) (& A)
 
-     SZ : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) → {y : Ordinal} (ya : odef A y) → ZChain A y f (SZ0 f mf ya)  (& A)
-     SZ f mf {y} ay = TransFinite {λ z → ZChain A y f (SZ0 f mf ay)  z  } (ind f mf ay (SZ0 f mf ay)  ) (& A)
+     SZ : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) → {y : Ordinal} (ay : odef A y) → ZChain A f ay (SZ0 f mf ay)  (& A)
+     SZ f mf {y} ay = TransFinite {λ z → ZChain A f ay (SZ0 f mf ay)  z  } (λ x → ind f mf ay x (SZ0 f mf ay)  ) (& A)
 
      zorn00 : Maximal A 
      zorn00 with is-o∅ ( & HasMaximal )  -- we have no Level (suc n) LEM 
@@ -678,9 +692,9 @@
          nmx mx =  ∅< {HasMaximal} zc5 ( ≡o∅→=od∅  ¬Maximal ) where
               zc5 : odef A (& (Maximal.maximal mx)) ∧ (( y : Ordinal ) →  odef A y → ¬ (* (& (Maximal.maximal mx)) < * y)) 
               zc5 = ⟪  Maximal.A∋maximal mx , (λ y ay mx<y → Maximal.¬maximal<x mx (subst (λ k → odef A k ) (sym &iso) ay) (subst (λ k → k < * y) *iso mx<y) ) ⟫
-         zc0 : ZChain0 A 
-         zc0 = TransFinite {λ z → ZChain1 z} (sind (cf nmx) (cf-is-≤-monotonic nmx)  (subst (λ k → odef A k ) &iso as )) (& A)
-         zorn04 : ZChain A (& s) (cf nmx) zc0 (& A)
+         zc0 : ZChain1 A  (cf nmx) as0 (& A)
+         zc0 = TransFinite {λ z → ZChain1 A (cf nmx) as0 z} (sind (cf nmx) (cf-is-≤-monotonic nmx)  as0) (& A)
+         zorn04 : ZChain A (cf nmx) as0 zc0 (& A)
          zorn04 = SZ (cf nmx) (cf-is-≤-monotonic nmx) (subst (λ k → odef A k ) &iso as ) 
          total : IsTotalOrderSet (ZChain.chain zorn04)
          total {a} {b} = zorn06  where