Mercurial > hg > Members > kono > Proof > ZF-in-agda
annotate src/zorn.agda @ 757:359f1577f947
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author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
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date | Sun, 24 Jul 2022 15:25:08 +0900 |
parents | 60a2340e892d |
children | a2947dfff80d |
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478 | 1 {-# OPTIONS --allow-unsolved-metas #-} |
508 | 2 open import Level hiding ( suc ; zero ) |
431 | 3 open import Ordinals |
552 | 4 open import Relation.Binary |
5 open import Relation.Binary.Core | |
6 open import Relation.Binary.PropositionalEquality | |
497 | 7 import OD |
552 | 8 module zorn {n : Level } (O : Ordinals {n}) (_<_ : (x y : OD.HOD O ) → Set n ) (PO : IsStrictPartialOrder _≡_ _<_ ) where |
431 | 9 |
560 | 10 -- |
11 -- Zorn-lemma : { A : HOD } | |
12 -- → o∅ o< & A | |
13 -- → ( ( B : HOD) → (B⊆A : B ⊆ A) → IsTotalOrderSet B → SUP A B ) -- SUP condition | |
14 -- → Maximal A | |
15 -- | |
16 | |
431 | 17 open import zf |
477 | 18 open import logic |
19 -- open import partfunc {n} O | |
20 | |
21 open import Relation.Nullary | |
22 open import Data.Empty | |
23 import BAlgbra | |
431 | 24 |
555 | 25 open import Data.Nat hiding ( _<_ ; _≤_ ) |
26 open import Data.Nat.Properties | |
27 open import nat | |
28 | |
431 | 29 |
30 open inOrdinal O | |
31 open OD O | |
32 open OD.OD | |
33 open ODAxiom odAxiom | |
477 | 34 import OrdUtil |
35 import ODUtil | |
431 | 36 open Ordinals.Ordinals O |
37 open Ordinals.IsOrdinals isOrdinal | |
38 open Ordinals.IsNext isNext | |
39 open OrdUtil O | |
477 | 40 open ODUtil O |
41 | |
42 | |
43 import ODC | |
44 | |
45 open _∧_ | |
46 open _∨_ | |
47 open Bool | |
431 | 48 |
49 open HOD | |
50 | |
560 | 51 -- |
52 -- Partial Order on HOD ( possibly limited in A ) | |
53 -- | |
54 | |
571 | 55 _<<_ : (x y : Ordinal ) → Set n -- Set n order |
570 | 56 x << y = * x < * y |
57 | |
58 POO : IsStrictPartialOrder _≡_ _<<_ | |
59 POO = record { isEquivalence = record { refl = refl ; sym = sym ; trans = trans } | |
60 ; trans = IsStrictPartialOrder.trans PO | |
61 ; irrefl = λ x=y x<y → IsStrictPartialOrder.irrefl PO (cong (*) x=y) x<y | |
62 ; <-resp-≈ = record { fst = λ {x} {y} {y1} y=y1 xy1 → subst (λ k → x << k ) y=y1 xy1 ; snd = λ {x} {x1} {y} x=x1 x1y → subst (λ k → k << x ) x=x1 x1y } } | |
63 | |
528
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64 _≤_ : (x y : HOD) → Set (Level.suc n) |
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65 x ≤ y = ( x ≡ y ) ∨ ( x < y ) |
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TransitiveClosure with x <= f x is possible
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66 |
554 | 67 ≤-ftrans : {x y z : HOD} → x ≤ y → y ≤ z → x ≤ z |
68 ≤-ftrans {x} {y} {z} (case1 refl ) (case1 refl ) = case1 refl | |
69 ≤-ftrans {x} {y} {z} (case1 refl ) (case2 y<z) = case2 y<z | |
70 ≤-ftrans {x} {_} {z} (case2 x<y ) (case1 refl ) = case2 x<y | |
71 ≤-ftrans {x} {y} {z} (case2 x<y) (case2 y<z) = case2 ( IsStrictPartialOrder.trans PO x<y y<z ) | |
72 | |
556 | 73 <-irr : {a b : HOD} → (a ≡ b ) ∨ (a < b ) → b < a → ⊥ |
74 <-irr {a} {b} (case1 a=b) b<a = IsStrictPartialOrder.irrefl PO (sym a=b) b<a | |
75 <-irr {a} {b} (case2 a<b) b<a = IsStrictPartialOrder.irrefl PO refl | |
76 (IsStrictPartialOrder.trans PO b<a a<b) | |
490 | 77 |
561 | 78 ptrans = IsStrictPartialOrder.trans PO |
79 | |
492 | 80 open _==_ |
81 open _⊆_ | |
82 | |
530 | 83 -- |
560 | 84 -- Closure of ≤-monotonic function f has total order |
530 | 85 -- |
86 | |
87 ≤-monotonic-f : (A : HOD) → ( Ordinal → Ordinal ) → Set (Level.suc n) | |
88 ≤-monotonic-f A f = (x : Ordinal ) → odef A x → ( * x ≤ * (f x) ) ∧ odef A (f x ) | |
89 | |
551 | 90 data FClosure (A : HOD) (f : Ordinal → Ordinal ) (s : Ordinal) : Ordinal → Set n where |
600 | 91 init : odef A s → FClosure A f s s |
555 | 92 fsuc : (x : Ordinal) ( p : FClosure A f s x ) → FClosure A f s (f x) |
554 | 93 |
556 | 94 A∋fc : {A : HOD} (s : Ordinal) {y : Ordinal } (f : Ordinal → Ordinal) (mf : ≤-monotonic-f A f) → (fcy : FClosure A f s y ) → odef A y |
600 | 95 A∋fc {A} s f mf (init as) = as |
556 | 96 A∋fc {A} s f mf (fsuc y fcy) = proj2 (mf y ( A∋fc {A} s f mf fcy ) ) |
555 | 97 |
714 | 98 A∋fcs : {A : HOD} (s : Ordinal) {y : Ordinal } (f : Ordinal → Ordinal) (mf : ≤-monotonic-f A f) → (fcy : FClosure A f s y ) → odef A s |
99 A∋fcs {A} s f mf (init as) = as | |
100 A∋fcs {A} s f mf (fsuc y fcy) = A∋fcs {A} s f mf fcy | |
101 | |
556 | 102 s≤fc : {A : HOD} (s : Ordinal ) {y : Ordinal } (f : Ordinal → Ordinal) (mf : ≤-monotonic-f A f) → (fcy : FClosure A f s y ) → * s ≤ * y |
600 | 103 s≤fc {A} s {.s} f mf (init x) = case1 refl |
556 | 104 s≤fc {A} s {.(f x)} f mf (fsuc x fcy) with proj1 (mf x (A∋fc s f mf fcy ) ) |
105 ... | case1 x=fx = subst (λ k → * s ≤ * k ) (*≡*→≡ x=fx) ( s≤fc {A} s f mf fcy ) | |
106 ... | case2 x<fx with s≤fc {A} s f mf fcy | |
107 ... | case1 s≡x = case2 ( subst₂ (λ j k → j < k ) (sym s≡x) refl x<fx ) | |
108 ... | case2 s<x = case2 ( IsStrictPartialOrder.trans PO s<x x<fx ) | |
555 | 109 |
557 | 110 fcn : {A : HOD} (s : Ordinal) { x : Ordinal} {f : Ordinal → Ordinal} → (mf : ≤-monotonic-f A f) → FClosure A f s x → ℕ |
600 | 111 fcn s mf (init as) = zero |
558 | 112 fcn {A} s {x} {f} mf (fsuc y p) with proj1 (mf y (A∋fc s f mf p)) |
113 ... | case1 eq = fcn s mf p | |
114 ... | case2 y<fy = suc (fcn s mf p ) | |
557 | 115 |
558 | 116 fcn-inject : {A : HOD} (s : Ordinal) { x y : Ordinal} {f : Ordinal → Ordinal} → (mf : ≤-monotonic-f A f) |
117 → (cx : FClosure A f s x ) (cy : FClosure A f s y ) → fcn s mf cx ≡ fcn s mf cy → * x ≡ * y | |
559 | 118 fcn-inject {A} s {x} {y} {f} mf cx cy eq = fc00 (fcn s mf cx) (fcn s mf cy) eq cx cy refl refl where |
119 fc00 : (i j : ℕ ) → i ≡ j → {x y : Ordinal } → (cx : FClosure A f s x ) (cy : FClosure A f s y ) → i ≡ fcn s mf cx → j ≡ fcn s mf cy → * x ≡ * y | |
600 | 120 fc00 zero zero refl (init _) (init x₁) i=x i=y = refl |
121 fc00 zero zero refl (init as) (fsuc y cy) i=x i=y with proj1 (mf y (A∋fc s f mf cy ) ) | |
122 ... | case1 y=fy = subst (λ k → * s ≡ k ) y=fy ( fc00 zero zero refl (init as) cy i=x i=y ) | |
123 fc00 zero zero refl (fsuc x cx) (init as) i=x i=y with proj1 (mf x (A∋fc s f mf cx ) ) | |
124 ... | case1 x=fx = subst (λ k → k ≡ * s ) x=fx ( fc00 zero zero refl cx (init as) i=x i=y ) | |
559 | 125 fc00 zero zero refl (fsuc x cx) (fsuc y cy) i=x i=y with proj1 (mf x (A∋fc s f mf cx ) ) | proj1 (mf y (A∋fc s f mf cy ) ) |
126 ... | case1 x=fx | case1 y=fy = subst₂ (λ j k → j ≡ k ) x=fx y=fy ( fc00 zero zero refl cx cy i=x i=y ) | |
127 fc00 (suc i) (suc j) i=j {.(f x)} {.(f y)} (fsuc x cx) (fsuc y cy) i=x j=y with proj1 (mf x (A∋fc s f mf cx ) ) | proj1 (mf y (A∋fc s f mf cy ) ) | |
128 ... | case1 x=fx | case1 y=fy = subst₂ (λ j k → j ≡ k ) x=fx y=fy ( fc00 (suc i) (suc j) i=j cx cy i=x j=y ) | |
129 ... | case1 x=fx | case2 y<fy = subst (λ k → k ≡ * (f y)) x=fx (fc02 x cx i=x) where | |
130 fc02 : (x1 : Ordinal) → (cx1 : FClosure A f s x1 ) → suc i ≡ fcn s mf cx1 → * x1 ≡ * (f y) | |
131 fc02 .(f x1) (fsuc x1 cx1) i=x1 with proj1 (mf x1 (A∋fc s f mf cx1 ) ) | |
560 | 132 ... | case1 eq = trans (sym eq) ( fc02 x1 cx1 i=x1 ) -- derefence while f x ≡ x |
559 | 133 ... | case2 lt = subst₂ (λ j k → * (f j) ≡ * (f k )) &iso &iso ( cong (λ k → * ( f (& k ))) fc04) where |
134 fc04 : * x1 ≡ * y | |
135 fc04 = fc00 i j (cong pred i=j) cx1 cy (cong pred i=x1) (cong pred j=y) | |
136 ... | case2 x<fx | case1 y=fy = subst (λ k → * (f x) ≡ k ) y=fy (fc03 y cy j=y) where | |
137 fc03 : (y1 : Ordinal) → (cy1 : FClosure A f s y1 ) → suc j ≡ fcn s mf cy1 → * (f x) ≡ * y1 | |
138 fc03 .(f y1) (fsuc y1 cy1) j=y1 with proj1 (mf y1 (A∋fc s f mf cy1 ) ) | |
139 ... | case1 eq = trans ( fc03 y1 cy1 j=y1 ) eq | |
140 ... | case2 lt = subst₂ (λ j k → * (f j) ≡ * (f k )) &iso &iso ( cong (λ k → * ( f (& k ))) fc05) where | |
141 fc05 : * x ≡ * y1 | |
142 fc05 = fc00 i j (cong pred i=j) cx cy1 (cong pred i=x) (cong pred j=y1) | |
143 ... | case2 x₁ | case2 x₂ = subst₂ (λ j k → * (f j) ≡ * (f k) ) &iso &iso (cong (λ k → * (f (& k))) (fc00 i j (cong pred i=j) cx cy (cong pred i=x) (cong pred j=y))) | |
557 | 144 |
600 | 145 |
557 | 146 fcn-< : {A : HOD} (s : Ordinal ) { x y : Ordinal} {f : Ordinal → Ordinal} → (mf : ≤-monotonic-f A f) |
147 → (cx : FClosure A f s x ) (cy : FClosure A f s y ) → fcn s mf cx Data.Nat.< fcn s mf cy → * x < * y | |
558 | 148 fcn-< {A} s {x} {y} {f} mf cx cy x<y = fc01 (fcn s mf cy) cx cy refl x<y where |
149 fc01 : (i : ℕ ) → {y : Ordinal } → (cx : FClosure A f s x ) (cy : FClosure A f s y ) → (i ≡ fcn s mf cy ) → fcn s mf cx Data.Nat.< i → * x < * y | |
150 fc01 (suc i) {y} cx (fsuc y1 cy) i=y (s≤s x<i) with proj1 (mf y1 (A∋fc s f mf cy ) ) | |
151 ... | case1 y=fy = subst (λ k → * x < k ) y=fy ( fc01 (suc i) {y1} cx cy i=y (s≤s x<i) ) | |
152 ... | case2 y<fy with <-cmp (fcn s mf cx ) i | |
153 ... | tri> ¬a ¬b c = ⊥-elim ( nat-≤> x<i c ) | |
154 ... | tri≈ ¬a b ¬c = subst (λ k → k < * (f y1) ) (fcn-inject s mf cy cx (sym (trans b (cong pred i=y) ))) y<fy | |
155 ... | tri< a ¬b ¬c = IsStrictPartialOrder.trans PO fc02 y<fy where | |
156 fc03 : suc i ≡ suc (fcn s mf cy) → i ≡ fcn s mf cy | |
157 fc03 eq = cong pred eq | |
158 fc02 : * x < * y1 | |
159 fc02 = fc01 i cx cy (fc03 i=y ) a | |
557 | 160 |
559 | 161 fcn-cmp : {A : HOD} (s : Ordinal) { x y : Ordinal } (f : Ordinal → Ordinal) (mf : ≤-monotonic-f A f) |
554 | 162 → (cx : FClosure A f s x) → (cy : FClosure A f s y ) → Tri (* x < * y) (* x ≡ * y) (* y < * x ) |
559 | 163 fcn-cmp {A} s {x} {y} f mf cx cy with <-cmp ( fcn s mf cx ) (fcn s mf cy ) |
164 ... | tri< a ¬b ¬c = tri< fc11 (λ eq → <-irr (case1 (sym eq)) fc11) (λ lt → <-irr (case2 fc11) lt) where | |
165 fc11 : * x < * y | |
166 fc11 = fcn-< {A} s {x} {y} {f} mf cx cy a | |
167 ... | tri≈ ¬a b ¬c = tri≈ (λ lt → <-irr (case1 (sym fc10)) lt) fc10 (λ lt → <-irr (case1 fc10) lt) where | |
168 fc10 : * x ≡ * y | |
169 fc10 = fcn-inject {A} s {x} {y} {f} mf cx cy b | |
170 ... | tri> ¬a ¬b c = tri> (λ lt → <-irr (case2 fc12) lt) (λ eq → <-irr (case1 eq) fc12) fc12 where | |
171 fc12 : * y < * x | |
172 fc12 = fcn-< {A} s {y} {x} {f} mf cy cx c | |
173 | |
600 | 174 |
562 | 175 fcn-imm : {A : HOD} (s : Ordinal) { x y : Ordinal } (f : Ordinal → Ordinal) (mf : ≤-monotonic-f A f) |
176 → (cx : FClosure A f s x) → (cy : FClosure A f s y ) → ¬ ( ( * x < * y ) ∧ ( * y < * (f x )) ) | |
563 | 177 fcn-imm {A} s {x} {y} f mf cx cy ⟪ x<y , y<fx ⟫ = fc21 where |
178 fc20 : fcn s mf cy Data.Nat.< suc (fcn s mf cx) → (fcn s mf cy ≡ fcn s mf cx) ∨ ( fcn s mf cy Data.Nat.< fcn s mf cx ) | |
179 fc20 y<sx with <-cmp ( fcn s mf cy ) (fcn s mf cx ) | |
180 ... | tri< a ¬b ¬c = case2 a | |
181 ... | tri≈ ¬a b ¬c = case1 b | |
182 ... | tri> ¬a ¬b c = ⊥-elim ( nat-≤> y<sx (s≤s c)) | |
183 fc17 : {x y : Ordinal } → (cx : FClosure A f s x) → (cy : FClosure A f s y ) → suc (fcn s mf cx) ≡ fcn s mf cy → * (f x ) ≡ * y | |
184 fc17 {x} {y} cx cy sx=y = fc18 (fcn s mf cy) cx cy refl sx=y where | |
185 fc18 : (i : ℕ ) → {y : Ordinal } → (cx : FClosure A f s x ) (cy : FClosure A f s y ) → (i ≡ fcn s mf cy ) → suc (fcn s mf cx) ≡ i → * (f x) ≡ * y | |
186 fc18 (suc i) {y} cx (fsuc y1 cy) i=y sx=i with proj1 (mf y1 (A∋fc s f mf cy ) ) | |
187 ... | case1 y=fy = subst (λ k → * (f x) ≡ k ) y=fy ( fc18 (suc i) {y1} cx cy i=y sx=i) -- dereference | |
188 ... | case2 y<fy = subst₂ (λ j k → * (f j) ≡ * (f k) ) &iso &iso (cong (λ k → * (f (& k) ) ) fc19) where | |
189 fc19 : * x ≡ * y1 | |
190 fc19 = fcn-inject s mf cx cy (cong pred ( trans sx=i i=y )) | |
191 fc21 : ⊥ | |
192 fc21 with <-cmp (suc ( fcn s mf cx )) (fcn s mf cy ) | |
193 ... | tri< a ¬b ¬c = <-irr (case2 y<fx) (fc22 a) where -- suc ncx < ncy | |
194 cxx : FClosure A f s (f x) | |
195 cxx = fsuc x cx | |
196 fc16 : (x : Ordinal ) → (cx : FClosure A f s x) → (fcn s mf cx ≡ fcn s mf (fsuc x cx)) ∨ ( suc (fcn s mf cx ) ≡ fcn s mf (fsuc x cx)) | |
600 | 197 fc16 x (init as) with proj1 (mf s as ) |
563 | 198 ... | case1 _ = case1 refl |
199 ... | case2 _ = case2 refl | |
200 fc16 .(f x) (fsuc x cx ) with proj1 (mf (f x) (A∋fc s f mf (fsuc x cx)) ) | |
201 ... | case1 _ = case1 refl | |
202 ... | case2 _ = case2 refl | |
203 fc22 : (suc ( fcn s mf cx )) Data.Nat.< (fcn s mf cy ) → * (f x) < * y | |
204 fc22 a with fc16 x cx | |
205 ... | case1 eq = fcn-< s mf cxx cy (subst (λ k → k Data.Nat.< fcn s mf cy ) eq (<-trans a<sa a)) | |
206 ... | case2 eq = fcn-< s mf cxx cy (subst (λ k → k Data.Nat.< fcn s mf cy ) eq a ) | |
207 ... | tri≈ ¬a b ¬c = <-irr (case1 (fc17 cx cy b)) y<fx | |
208 ... | tri> ¬a ¬b c with fc20 c -- ncy < suc ncx | |
209 ... | case1 y=x = <-irr (case1 ( fcn-inject s mf cy cx y=x )) x<y | |
210 ... | case2 y<x = <-irr (case2 x<y) (fcn-< s mf cy cx y<x ) | |
211 | |
729 | 212 fc-conv : (A : HOD ) (f : Ordinal → Ordinal) {b u : Ordinal } |
213 → {p0 p1 : Ordinal → Ordinal} | |
214 → p0 u ≡ p1 u | |
215 → FClosure A f (p0 u) b → FClosure A f (p1 u) b | |
216 fc-conv A f {.(p0 u)} {u} {p0} {p1} p0u=p1u (init ap0u) = subst (λ k → FClosure A f (p1 u) k) (sym p0u=p1u) | |
217 ( init (subst (λ k → odef A k) p0u=p1u ap0u )) | |
218 fc-conv A f {_} {u} {p0} {p1} p0u=p1u (fsuc z fc) = fsuc z (fc-conv A f {_} {u} {p0} {p1} p0u=p1u fc) | |
219 | |
560 | 220 -- open import Relation.Binary.Properties.Poset as Poset |
221 | |
222 IsTotalOrderSet : ( A : HOD ) → Set (Level.suc n) | |
223 IsTotalOrderSet A = {a b : HOD} → odef A (& a) → odef A (& b) → Tri (a < b) (a ≡ b) (b < a ) | |
224 | |
567 | 225 ⊆-IsTotalOrderSet : { A B : HOD } → B ⊆ A → IsTotalOrderSet A → IsTotalOrderSet B |
568 | 226 ⊆-IsTotalOrderSet {A} {B} B⊆A T ax ay = T (incl B⊆A ax) (incl B⊆A ay) |
567 | 227 |
568 | 228 _⊆'_ : ( A B : HOD ) → Set n |
229 _⊆'_ A B = {x : Ordinal } → odef A x → odef B x | |
560 | 230 |
231 -- | |
232 -- inductive maxmum tree from x | |
233 -- tree structure | |
234 -- | |
554 | 235 |
567 | 236 record HasPrev (A B : HOD) {x : Ordinal } (xa : odef A x) ( f : Ordinal → Ordinal ) : Set n where |
533 | 237 field |
534 | 238 y : Ordinal |
541 | 239 ay : odef B y |
534 | 240 x=fy : x ≡ f y |
529 | 241 |
570 | 242 record IsSup (A B : HOD) {x : Ordinal } (xa : odef A x) : Set n where |
654 | 243 field |
571 | 244 x<sup : {y : Ordinal} → odef B y → (y ≡ x ) ∨ (y << x ) |
568 | 245 |
656 | 246 record SUP ( A B : HOD ) : Set (Level.suc n) where |
247 field | |
248 sup : HOD | |
249 A∋maximal : A ∋ sup | |
250 x<sup : {x : HOD} → B ∋ x → (x ≡ sup ) ∨ (x < sup ) -- B is Total, use positive | |
251 | |
690 | 252 -- |
253 -- sup and its fclosure is in a chain HOD | |
254 -- chain HOD is sorted by sup as Ordinal and <-ordered | |
255 -- whole chain is a union of separated Chain | |
256 -- minimum index is y not ϕ | |
257 -- | |
258 | |
714 | 259 record ChainP (A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) {y : Ordinal} (ay : odef A y) (supf : Ordinal → Ordinal) (u z : Ordinal) : Set n where |
690 | 260 field |
739 | 261 csupz : FClosure A f (supf u) z |
756 | 262 supfu=u : supf u ≡ u |
263 fcy<sup : {z : Ordinal } → FClosure A f y z → z << supf u -- not a initial chain | |
714 | 264 order : {sup1 z1 : Ordinal} → (lt : sup1 o< u ) → FClosure A f (supf sup1 ) z1 → z1 << supf u |
694 | 265 |
266 -- Union of supf z which o< x | |
267 -- | |
690 | 268 |
748 | 269 data UChain ( A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) {y : Ordinal } (ay : odef A y ) |
270 (supf : Ordinal → Ordinal) (x : Ordinal) : (z : Ordinal) → Set n where | |
271 ch-init : {z : Ordinal } (fc : FClosure A f y z) → UChain A f mf ay supf x z | |
756 | 272 ch-is-sup : (u : Ordinal) {z : Ordinal } (u≤x : u o≤ x ) ( is-sup : ChainP A f mf ay supf u z) |
748 | 273 ( fc : FClosure A f (supf u) z ) → UChain A f mf ay supf x z |
694 | 274 |
275 ∈∧P→o< : {A : HOD } {y : Ordinal} → {P : Set n} → odef A y ∧ P → y o< & A | |
276 ∈∧P→o< {A } {y} p = subst (λ k → k o< & A) &iso ( c<→o< (subst (λ k → odef A k ) (sym &iso ) (proj1 p ))) | |
277 | |
278 UnionCF : ( A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) {y : Ordinal } (ay : odef A y ) | |
279 ( supf : Ordinal → Ordinal ) ( x : Ordinal ) → HOD | |
280 UnionCF A f mf ay supf x | |
281 = record { od = record { def = λ z → odef A z ∧ UChain A f mf ay supf x z } ; odmax = & A ; <odmax = λ {y} sy → ∈∧P→o< sy } | |
662 | 282 |
703 | 283 record ZChain ( A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) |
284 {init : Ordinal} (ay : odef A init) ( z : Ordinal ) : Set (Level.suc n) where | |
655 | 285 field |
694 | 286 supf : Ordinal → Ordinal |
608
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mutual tranfinite in zorn
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287 chain : HOD |
703 | 288 chain = UnionCF A f mf ay supf z |
568 | 289 field |
290 chain⊆A : chain ⊆' A | |
653 | 291 chain∋init : odef chain init |
292 initial : {y : Ordinal } → odef chain y → * init ≤ * y | |
568 | 293 f-next : {a : Ordinal } → odef chain a → odef chain (f a) |
654 | 294 f-total : IsTotalOrderSet chain |
756 | 295 |
754 | 296 csupf : {z : Ordinal } → odef chain (supf z) |
756 | 297 sup=u : {b : Ordinal} → {ab : odef A b} → b o< z → IsSup A (UnionCF A f mf ay supf (osuc b)) ab → supf b ≡ b |
298 fcy<sup : {u w : Ordinal } → u o< z → FClosure A f init w → w << supf u -- different from order because y o< supf | |
299 order : {b sup1 z1 : Ordinal} → b o< z → sup1 o≤ b → FClosure A f (supf sup1) z1 → z1 << supf b | |
300 | |
653 | 301 |
728 | 302 record ZChain1 ( A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) |
303 {init : Ordinal} (ay : odef A init) (zc : ZChain A f mf ay (& A)) ( z : Ordinal ) : Set (Level.suc n) where | |
304 field | |
305 is-max : {a b : Ordinal } → (ca : odef (UnionCF A f mf ay (ZChain.supf zc) z) a ) → b o< z → (ab : odef A b) | |
306 → HasPrev A (UnionCF A f mf ay (ZChain.supf zc) z) ab f ∨ IsSup A (UnionCF A f mf ay (ZChain.supf zc) z) ab | |
307 → * a < * b → odef ((UnionCF A f mf ay (ZChain.supf zc) z)) b | |
308 | |
568 | 309 record Maximal ( A : HOD ) : Set (Level.suc n) where |
310 field | |
311 maximal : HOD | |
312 A∋maximal : A ∋ maximal | |
313 ¬maximal<x : {x : HOD} → A ∋ x → ¬ maximal < x -- A is Partial, use negative | |
567 | 314 |
748 | 315 -- data UChain is total |
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parents:
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316 |
694 | 317 chain-total : (A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) {y : Ordinal} (ay : odef A y) (supf : Ordinal → Ordinal ) |
748 | 318 {s s1 a b : Ordinal } ( ca : UChain A f mf ay supf s a ) ( cb : UChain A f mf ay supf s1 b ) → Tri (* a < * b) (* a ≡ * b) (* b < * a ) |
694 | 319 chain-total A f mf {y} ay supf {xa} {xb} {a} {b} ca cb = ct-ind xa xb ca cb where |
748 | 320 ct-ind : (xa xb : Ordinal) → {a b : Ordinal} → UChain A f mf ay supf xa a → UChain A f mf ay supf xb b → Tri (* a < * b) (* a ≡ * b) (* b < * a) |
321 ct-ind xa xb {a} {b} (ch-init fca) (ch-init fcb) = fcn-cmp y f mf fca fcb | |
322 ct-ind xa xb {a} {b} (ch-init fca) (ch-is-sup ub ub<x supb fcb) = tri< ct01 (λ eq → <-irr (case1 (sym eq)) ct01) (λ lt → <-irr (case2 ct01) lt) where | |
323 ct00 : * a < * (supf ub) | |
695 | 324 ct00 = ChainP.fcy<sup supb fca |
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325 ct01 : * a < * b |
748 | 326 ct01 with s≤fc (supf ub) f mf fcb |
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327 ... | case1 eq = subst (λ k → * a < k ) eq ct00 |
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328 ... | case2 lt = IsStrictPartialOrder.trans POO ct00 lt |
748 | 329 ct-ind xa xb {a} {b} (ch-is-sup ua ua<x supa fca) (ch-init fcb)= tri> (λ lt → <-irr (case2 ct01) lt) (λ eq → <-irr (case1 eq) ct01) ct01 where |
749 | 330 ct00 : * b < * (supf ua) |
331 ct00 = ChainP.fcy<sup supa fcb | |
689
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parents:
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332 ct01 : * b < * a |
749 | 333 ct01 with s≤fc (supf ua) f mf fca |
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334 ... | case1 eq = subst (λ k → * b < k ) eq ct00 |
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335 ... | case2 lt = IsStrictPartialOrder.trans POO ct00 lt |
748 | 336 ct-ind xa xb {a} {b} (ch-is-sup ua ua<x supa fca) (ch-is-sup ub ub<x supb fcb) with trio< ua ub |
685 | 337 ... | tri< a₁ ¬b ¬c = tri< ct02 (λ eq → <-irr (case1 (sym eq)) ct02) (λ lt → <-irr (case2 ct02) lt) where |
748 | 338 ct03 : * a < * (supf ub) |
339 ct03 = ChainP.order supb a₁ (ChainP.csupz supa) | |
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340 ct02 : * a < * b |
748 | 341 ct02 with s≤fc (supf ub) f mf fcb |
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342 ... | case1 eq = subst (λ k → * a < k ) eq ct03 |
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343 ... | case2 lt = IsStrictPartialOrder.trans POO ct03 lt |
749 | 344 ... | tri≈ ¬a refl ¬c = fcn-cmp (supf ua) f mf fca fcb |
685 | 345 ... | tri> ¬a ¬b c = tri> (λ lt → <-irr (case2 ct04) lt) (λ eq → <-irr (case1 (eq)) ct04) ct04 where |
749 | 346 ct05 : * b < * (supf ua) |
347 ct05 = ChainP.order supa c (ChainP.csupz supb) | |
689
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348 ct04 : * b < * a |
749 | 349 ct04 with s≤fc (supf ua) f mf fca |
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350 ... | case1 eq = subst (λ k → * b < k ) eq ct05 |
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351 ... | case2 lt = IsStrictPartialOrder.trans POO ct05 lt |
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parents:
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352 |
743 | 353 init-uchain : (A : HOD) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) {y : Ordinal } → (ay : odef A y ) |
354 { supf : Ordinal → Ordinal } { x : Ordinal } → odef (UnionCF A f mf ay supf x) y | |
748 | 355 init-uchain A f mf ay = ⟪ ay , ch-init (init ay) ⟫ |
743 | 356 |
698 | 357 ChainP-next : (A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) {y : Ordinal} (ay : odef A y) (supf : Ordinal → Ordinal ) |
358 → {x z : Ordinal } → ChainP A f mf ay supf x z → ChainP A f mf ay supf x (f z ) | |
756 | 359 ChainP-next A f mf {y} ay supf {x} {z} cp = record { supfu=u = ChainP.supfu=u cp |
746 | 360 ; fcy<sup = ChainP.fcy<sup cp ; csupz = fsuc _ (ChainP.csupz cp) ; order = ChainP.order cp } |
698 | 361 |
497 | 362 Zorn-lemma : { A : HOD } |
464 | 363 → o∅ o< & A |
568 | 364 → ( ( B : HOD) → (B⊆A : B ⊆' A) → IsTotalOrderSet B → SUP A B ) -- SUP condition |
497 | 365 → Maximal A |
552 | 366 Zorn-lemma {A} 0<A supP = zorn00 where |
571 | 367 <-irr0 : {a b : HOD} → A ∋ a → A ∋ b → (a ≡ b ) ∨ (a < b ) → b < a → ⊥ |
368 <-irr0 {a} {b} A∋a A∋b = <-irr | |
537 | 369 z07 : {y : Ordinal} → {P : Set n} → odef A y ∧ P → y o< & A |
370 z07 {y} p = subst (λ k → k o< & A) &iso ( c<→o< (subst (λ k → odef A k ) (sym &iso ) (proj1 p ))) | |
530 | 371 s : HOD |
372 s = ODC.minimal O A (λ eq → ¬x<0 ( subst (λ k → o∅ o< k ) (=od∅→≡o∅ eq) 0<A )) | |
568 | 373 as : A ∋ * ( & s ) |
374 as = subst (λ k → odef A (& k) ) (sym *iso) ( ODC.x∋minimal O A (λ eq → ¬x<0 ( subst (λ k → o∅ o< k ) (=od∅→≡o∅ eq) 0<A )) ) | |
608
6655f03984f9
mutual tranfinite in zorn
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parents:
607
diff
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375 as0 : odef A (& s ) |
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376 as0 = subst (λ k → odef A k ) &iso as |
547 | 377 s<A : & s o< & A |
568 | 378 s<A = c<→o< (subst (λ k → odef A (& k) ) *iso as ) |
530 | 379 HasMaximal : HOD |
537 | 380 HasMaximal = record { od = record { def = λ x → odef A x ∧ ( (m : Ordinal) → odef A m → ¬ (* x < * m)) } ; odmax = & A ; <odmax = z07 } |
381 no-maximum : HasMaximal =h= od∅ → (x : Ordinal) → odef A x ∧ ((m : Ordinal) → odef A m → odef A x ∧ (¬ (* x < * m) )) → ⊥ | |
382 no-maximum nomx x P = ¬x<0 (eq→ nomx {x} ⟪ proj1 P , (λ m ma p → proj2 ( proj2 P m ma ) p ) ⟫ ) | |
532 | 383 Gtx : { x : HOD} → A ∋ x → HOD |
537 | 384 Gtx {x} ax = record { od = record { def = λ y → odef A y ∧ (x < (* y)) } ; odmax = & A ; <odmax = z07 } |
385 z08 : ¬ Maximal A → HasMaximal =h= od∅ | |
386 z08 nmx = record { eq→ = λ {x} lt → ⊥-elim ( nmx record {maximal = * x ; A∋maximal = subst (λ k → odef A k) (sym &iso) (proj1 lt) | |
387 ; ¬maximal<x = λ {y} ay → subst (λ k → ¬ (* x < k)) *iso (proj2 lt (& y) ay) } ) ; eq← = λ {y} lt → ⊥-elim ( ¬x<0 lt )} | |
388 x-is-maximal : ¬ Maximal A → {x : Ordinal} → (ax : odef A x) → & (Gtx (subst (λ k → odef A k ) (sym &iso) ax)) ≡ o∅ → (m : Ordinal) → odef A m → odef A x ∧ (¬ (* x < * m)) | |
389 x-is-maximal nmx {x} ax nogt m am = ⟪ subst (λ k → odef A k) &iso (subst (λ k → odef A k ) (sym &iso) ax) , ¬x<m ⟫ where | |
390 ¬x<m : ¬ (* x < * m) | |
391 ¬x<m x<m = ∅< {Gtx (subst (λ k → odef A k ) (sym &iso) ax)} {* m} ⟪ subst (λ k → odef A k) (sym &iso) am , subst (λ k → * x < k ) (cong (*) (sym &iso)) x<m ⟫ (≡o∅→=od∅ nogt) | |
543 | 392 |
560 | 393 -- Uncountable ascending chain by axiom of choice |
530 | 394 cf : ¬ Maximal A → Ordinal → Ordinal |
532 | 395 cf nmx x with ODC.∋-p O A (* x) |
396 ... | no _ = o∅ | |
397 ... | yes ax with is-o∅ (& ( Gtx ax )) | |
538 | 398 ... | yes nogt = -- no larger element, so it is maximal |
399 ⊥-elim (no-maximum (z08 nmx) x ⟪ subst (λ k → odef A k) &iso ax , x-is-maximal nmx (subst (λ k → odef A k ) &iso ax) nogt ⟫ ) | |
532 | 400 ... | no not = & (ODC.minimal O (Gtx ax) (λ eq → not (=od∅→≡o∅ eq))) |
537 | 401 is-cf : (nmx : ¬ Maximal A ) → {x : Ordinal} → odef A x → odef A (cf nmx x) ∧ ( * x < * (cf nmx x) ) |
402 is-cf nmx {x} ax with ODC.∋-p O A (* x) | |
403 ... | no not = ⊥-elim ( not (subst (λ k → odef A k ) (sym &iso) ax )) | |
404 ... | yes ax with is-o∅ (& ( Gtx ax )) | |
405 ... | yes nogt = ⊥-elim (no-maximum (z08 nmx) x ⟪ subst (λ k → odef A k) &iso ax , x-is-maximal nmx (subst (λ k → odef A k ) &iso ax) nogt ⟫ ) | |
406 ... | no not = ODC.x∋minimal O (Gtx ax) (λ eq → not (=od∅→≡o∅ eq)) | |
606 | 407 |
408 --- | |
409 --- infintie ascention sequence of f | |
410 --- | |
530 | 411 cf-is-<-monotonic : (nmx : ¬ Maximal A ) → (x : Ordinal) → odef A x → ( * x < * (cf nmx x) ) ∧ odef A (cf nmx x ) |
537 | 412 cf-is-<-monotonic nmx x ax = ⟪ proj2 (is-cf nmx ax ) , proj1 (is-cf nmx ax ) ⟫ |
530 | 413 cf-is-≤-monotonic : (nmx : ¬ Maximal A ) → ≤-monotonic-f A ( cf nmx ) |
532 | 414 cf-is-≤-monotonic nmx x ax = ⟪ case2 (proj1 ( cf-is-<-monotonic nmx x ax )) , proj2 ( cf-is-<-monotonic nmx x ax ) ⟫ |
543 | 415 |
703 | 416 sp0 : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) (zc : ZChain A f mf as0 (& A) ) |
653 | 417 (total : IsTotalOrderSet (ZChain.chain zc) ) → SUP A (ZChain.chain zc) |
703 | 418 sp0 f mf zc total = supP (ZChain.chain zc) (ZChain.chain⊆A zc) total |
543 | 419 zc< : {x y z : Ordinal} → {P : Set n} → (x o< y → P) → x o< z → z o< y → P |
420 zc< {x} {y} {z} {P} prev x<z z<y = prev (ordtrans x<z z<y) | |
421 | |
728 | 422 SZ1 :( A : HOD ) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f) |
423 {init : Ordinal} (ay : odef A init) (zc : ZChain A f mf ay (& A)) (x : Ordinal) → ZChain1 A f mf ay zc x | |
424 SZ1 A f mf {y} ay zc x = TransFinite { λ x → ZChain1 A f mf ay zc x } zc1 x where | |
734 | 425 chain-mono2 : (x : Ordinal) {a b c : Ordinal} → a o≤ b → b o≤ x → |
426 odef (UnionCF A f mf ay (ZChain.supf zc) a) c → odef (UnionCF A f mf ay (ZChain.supf zc) b) c | |
748 | 427 chain-mono2 x {a} {b} {c} a≤b b≤x ⟪ ua , ch-init fc ⟫ = |
428 ⟪ ua , ch-init fc ⟫ | |
756 | 429 chain-mono2 x {a} {b} {c} a≤b b≤x ⟪ uaa , ch-is-sup ua u≤x is-sup fc ⟫ = |
430 ⟪ uaa , ch-is-sup ua (OrdTrans u≤x a≤b) is-sup fc ⟫ | |
743 | 431 chain<ZA : {x : Ordinal } → UnionCF A f mf ay (ZChain.supf zc) x ⊆' UnionCF A f mf ay (ZChain.supf zc) (& A) |
748 | 432 chain<ZA {x} ux with proj2 ux |
433 ... | ch-init fc = ⟪ proj1 ux , ch-init fc ⟫ | |
756 | 434 ... | ch-is-sup u pu≤x is-sup fc = ⟪ proj1 ux , ch-is-sup u (o<→≤ u≤x) is-sup fc ⟫ where |
749 | 435 u<A : (& ( * ( ZChain.supf zc u))) o< & A |
436 u<A = c<→o< (subst (λ k → odef A k ) (sym &iso) (A∋fcs _ f mf fc) ) | |
756 | 437 u≤x : u o< & A |
438 u≤x = subst (λ k → k o< & A ) (trans &iso (ChainP.supfu=u is-sup)) u<A | |
735 | 439 is-max-hp : (x : Ordinal) {a : Ordinal} {b : Ordinal} → odef (UnionCF A f mf ay (ZChain.supf zc) x) a → |
440 b o< x → (ab : odef A b) → | |
441 HasPrev A (UnionCF A f mf ay (ZChain.supf zc) x) ab f → | |
442 * a < * b → odef (UnionCF A f mf ay (ZChain.supf zc) x) b | |
749 | 443 is-max-hp x {a} {b} ua b<x ab has-prev a<b with HasPrev.ay has-prev |
444 ... | ⟪ ab0 , ch-init fc ⟫ = ⟪ ab , ch-init ( subst (λ k → FClosure A f y k) (sym (HasPrev.x=fy has-prev)) (fsuc _ fc )) ⟫ | |
756 | 445 ... | ⟪ ab0 , ch-is-sup u u≤x is-sup fc ⟫ = ⟪ ab , |
749 | 446 subst (λ k → UChain A f mf ay (ZChain.supf zc) x k ) |
756 | 447 (sym (HasPrev.x=fy has-prev)) ( ch-is-sup u u≤x (ChainP-next A f mf ay _ is-sup) (fsuc _ fc)) ⟫ |
728 | 448 zc1 : (x : Ordinal) → ((y₁ : Ordinal) → y₁ o< x → ZChain1 A f mf ay zc y₁) → ZChain1 A f mf ay zc x |
732
ddeb107b6f71
bchain can be reached from upwords by f. so it is worng.
Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
729
diff
changeset
|
449 zc1 x prev with Oprev-p x |
756 | 450 ... | yes op = record { is-max = is-max } where |
732
ddeb107b6f71
bchain can be reached from upwords by f. so it is worng.
Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
729
diff
changeset
|
451 px = Oprev.oprev op |
735 | 452 zc-b<x : (b : Ordinal ) → b o< x → b o< osuc px |
453 zc-b<x b lt = subst (λ k → b o< k ) (sym (Oprev.oprev=x op)) lt | |
754 | 454 fcy<sup : {u w : Ordinal} → u o< x → FClosure A f y w → w << ZChain.supf zc u |
756 | 455 fcy<sup {u} {w} u≤x fc = ? |
728 | 456 is-max : {a : Ordinal} {b : Ordinal} → odef (UnionCF A f mf ay (ZChain.supf zc) x) a → |
457 b o< x → (ab : odef A b) → | |
458 HasPrev A (UnionCF A f mf ay (ZChain.supf zc) x) ab f ∨ IsSup A (UnionCF A f mf ay (ZChain.supf zc) x) ab → | |
459 * a < * b → odef (UnionCF A f mf ay (ZChain.supf zc) x) b | |
735 | 460 is-max {a} {b} ua b<x ab (case1 has-prev) a<b = is-max-hp x {a} {b} ua b<x ab has-prev a<b |
733 | 461 is-max {a} {b} ua b<x ab (case2 is-sup) a<b with ODC.p∨¬p O ( HasPrev A (UnionCF A f mf ay (ZChain.supf zc) x) ab f ) |
735 | 462 ... | case1 has-prev = is-max-hp x {a} {b} ua b<x ab has-prev a<b |
734 | 463 ... | case2 ¬fy<x = m01 where |
735 | 464 px<x : px o< x |
465 px<x = subst (λ k → px o< k ) (Oprev.oprev=x op) <-osuc | |
728 | 466 m01 : odef (UnionCF A f mf ay (ZChain.supf zc) x) b |
736 | 467 m01 with trio< b px --- px < b < x |
468 ... | tri> ¬a ¬b c = ⊥-elim (¬p<x<op ⟪ c , subst (λ k → b o< k ) (sym (Oprev.oprev=x op)) b<x ⟫) | |
735 | 469 ... | tri< b<px ¬b ¬c = chain-mono2 x ( o<→≤ (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc )) o≤-refl m04 where |
470 m03 : odef (UnionCF A f mf ay (ZChain.supf zc) px) a | |
749 | 471 m03 with proj2 ua |
472 ... | ch-init fc = ⟪ proj1 ua , ch-init fc ⟫ | |
756 | 473 ... | ch-is-sup u u≤x is-sup fc with trio< u px |
755 | 474 ... | tri< a ¬b ¬c = ⟪ proj1 ua , ch-is-sup u (o<→≤ a) is-sup fc ⟫ -- u o< osuc x |
475 ... | tri≈ ¬a u=px ¬c = ⟪ proj1 ua , ch-is-sup u (o≤-refl0 u=px) is-sup fc ⟫ | |
476 ... | tri> ¬a ¬b c = ? -- u = x | |
728 | 477 m04 : odef (UnionCF A f mf ay (ZChain.supf zc) px) b |
735 | 478 m04 = ZChain1.is-max (prev px px<x) m03 b<px ab |
479 (case2 record {x<sup = λ {z} lt → IsSup.x<sup is-sup (chain-mono2 x ( o<→≤ (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc )) o≤-refl lt) } ) a<b | |
755 | 480 ... | tri≈ ¬a b=px ¬c = ? -- b = px case, u = px u< osuc x |
756 | 481 ... | no lim = record { is-max = is-max } where |
734 | 482 is-max : {a : Ordinal} {b : Ordinal} → odef (UnionCF A f mf ay (ZChain.supf zc) x) a → |
483 b o< x → (ab : odef A b) → | |
484 HasPrev A (UnionCF A f mf ay (ZChain.supf zc) x) ab f ∨ IsSup A (UnionCF A f mf ay (ZChain.supf zc) x) ab → | |
485 * a < * b → odef (UnionCF A f mf ay (ZChain.supf zc) x) b | |
735 | 486 is-max {a} {b} ua b<x ab (case1 has-prev) a<b = is-max-hp x {a} {b} ua b<x ab has-prev a<b |
743 | 487 is-max {a} {b} ua b<x ab (case2 is-sup) a<b with IsSup.x<sup is-sup (init-uchain A f mf ay ) |
488 ... | case1 b=y = ⊥-elim ( <-irr ( ZChain.initial zc (chain<ZA (chain-mono2 (osuc x) (o<→≤ <-osuc ) o≤-refl ua )) ) | |
489 (subst (λ k → * a < * k ) (sym b=y) a<b ) ) | |
744 | 490 ... | case2 y<b = chain-mono2 x (o<→≤ (ob<x lim b<x) ) o≤-refl m04 where |
740 | 491 m07 : {z : Ordinal} → FClosure A f y z → z << ZChain.supf zc b |
756 | 492 m07 {z} fc = ZChain.fcy<sup zc ? fc |
741 | 493 m08 : {sup1 z1 : Ordinal} → sup1 o< b → FClosure A f (ZChain.supf zc sup1) z1 → z1 << ZChain.supf zc b |
756 | 494 m08 {sup1} {z1} s<b fc = ZChain.order zc ? ? fc |
735 | 495 m05 : b ≡ ZChain.supf zc b |
756 | 496 m05 = sym (ZChain.sup=u zc {_} {ab} ? |
497 record { x<sup = λ lt → IsSup.x<sup is-sup (chain-mono2 x (o<→≤ (ob<x lim b<x)) o≤-refl lt )} ) -- ZChain on x | |
739 | 498 m06 : ChainP A f mf ay (ZChain.supf zc) b b |
756 | 499 m06 = record { fcy<sup = m07 ; csupz = subst (λ k → FClosure A f k b ) m05 (init ab) ; order = m08 |
744 | 500 ; supfu=u = sym m05 } |
735 | 501 m04 : odef (UnionCF A f mf ay (ZChain.supf zc) (osuc b)) b |
755 | 502 m04 = ⟪ ab , ch-is-sup b (ordtrans o≤-refl <-osuc) m06 (subst (λ k → FClosure A f k b) m05 (init ab)) ⟫ |
727 | 503 |
543 | 504 --- |
560 | 505 --- the maximum chain has fix point of any ≤-monotonic function |
543 | 506 --- |
703 | 507 fixpoint : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) (zc : ZChain A f mf as0 (& A) ) |
633
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508 → (total : IsTotalOrderSet (ZChain.chain zc) ) |
703 | 509 → f (& (SUP.sup (sp0 f mf zc total ))) ≡ & (SUP.sup (sp0 f mf zc total)) |
510 fixpoint f mf zc total = z14 where | |
538 | 511 chain = ZChain.chain zc |
703 | 512 sp1 = sp0 f mf zc total |
712 | 513 z10 : {a b : Ordinal } → (ca : odef chain a ) → b o< & A → (ab : odef A b ) |
570 | 514 → HasPrev A chain ab f ∨ IsSup A chain {b} ab -- (supO chain (ZChain.chain⊆A zc) (ZChain.f-total zc) ≡ b ) |
538 | 515 → * a < * b → odef chain b |
728 | 516 z10 = ZChain1.is-max (SZ1 A f mf as0 zc (& A) ) |
543 | 517 z11 : & (SUP.sup sp1) o< & A |
518 z11 = c<→o< ( SUP.A∋maximal sp1) | |
538 | 519 z12 : odef chain (& (SUP.sup sp1)) |
520 z12 with o≡? (& s) (& (SUP.sup sp1)) | |
653 | 521 ... | yes eq = subst (λ k → odef chain k) eq ( ZChain.chain∋init zc ) |
712 | 522 ... | no ne = z10 {& s} {& (SUP.sup sp1)} ( ZChain.chain∋init zc ) z11 (SUP.A∋maximal sp1) |
570 | 523 (case2 z19 ) z13 where |
538 | 524 z13 : * (& s) < * (& (SUP.sup sp1)) |
653 | 525 z13 with SUP.x<sup sp1 ( ZChain.chain∋init zc ) |
538 | 526 ... | case1 eq = ⊥-elim ( ne (cong (&) eq) ) |
527 ... | case2 lt = subst₂ (λ j k → j < k ) (sym *iso) (sym *iso) lt | |
570 | 528 z19 : IsSup A chain {& (SUP.sup sp1)} (SUP.A∋maximal sp1) |
571 | 529 z19 = record { x<sup = z20 } where |
530 z20 : {y : Ordinal} → odef chain y → (y ≡ & (SUP.sup sp1)) ∨ (y << & (SUP.sup sp1)) | |
531 z20 {y} zy with SUP.x<sup sp1 (subst (λ k → odef chain k ) (sym &iso) zy) | |
570 | 532 ... | case1 y=p = case1 (subst (λ k → k ≡ _ ) &iso ( cong (&) y=p )) |
533 ... | case2 y<p = case2 (subst (λ k → * y < k ) (sym *iso) y<p ) | |
534 -- λ {y} zy → subst (λ k → (y ≡ & k ) ∨ (y << & k)) ? (SUP.x<sup sp1 ? ) } | |
703 | 535 z14 : f (& (SUP.sup (sp0 f mf zc total ))) ≡ & (SUP.sup (sp0 f mf zc total )) |
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536 z14 with total (subst (λ k → odef chain k) (sym &iso) (ZChain.f-next zc z12 )) z12 |
631 | 537 ... | tri< a ¬b ¬c = ⊥-elim z16 where |
538 z16 : ⊥ | |
539 z16 with proj1 (mf (& ( SUP.sup sp1)) ( SUP.A∋maximal sp1 )) | |
540 ... | case1 eq = ⊥-elim (¬b (subst₂ (λ j k → j ≡ k ) refl *iso (sym eq) )) | |
541 ... | case2 lt = ⊥-elim (¬c (subst₂ (λ j k → k < j ) refl *iso lt )) | |
542 ... | tri≈ ¬a b ¬c = subst ( λ k → k ≡ & (SUP.sup sp1) ) &iso ( cong (&) b ) | |
543 ... | tri> ¬a ¬b c = ⊥-elim z17 where | |
544 z15 : (* (f ( & ( SUP.sup sp1 ))) ≡ SUP.sup sp1) ∨ (* (f ( & ( SUP.sup sp1 ))) < SUP.sup sp1) | |
545 z15 = SUP.x<sup sp1 (subst (λ k → odef chain k ) (sym &iso) (ZChain.f-next zc z12 )) | |
546 z17 : ⊥ | |
547 z17 with z15 | |
548 ... | case1 eq = ¬b eq | |
549 ... | case2 lt = ¬a lt | |
560 | 550 |
551 -- ZChain contradicts ¬ Maximal | |
552 -- | |
571 | 553 -- ZChain forces fix point on any ≤-monotonic function (fixpoint) |
560 | 554 -- ¬ Maximal create cf which is a <-monotonic function by axiom of choice. This contradicts fix point of ZChain |
555 -- | |
697 | 556 z04 : (nmx : ¬ Maximal A ) |
703 | 557 → (zc : ZChain A (cf nmx) (cf-is-≤-monotonic nmx) as0 (& A)) |
664 | 558 → IsTotalOrderSet (ZChain.chain zc) → ⊥ |
703 | 559 z04 nmx zc total = <-irr0 {* (cf nmx c)} {* c} (subst (λ k → odef A k ) (sym &iso) (proj1 (is-cf nmx (SUP.A∋maximal sp1 )))) |
571 | 560 (subst (λ k → odef A (& k)) (sym *iso) (SUP.A∋maximal sp1) ) |
703 | 561 (case1 ( cong (*)( fixpoint (cf nmx) (cf-is-≤-monotonic nmx ) zc total ))) -- x ≡ f x ̄ |
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562 (proj1 (cf-is-<-monotonic nmx c (SUP.A∋maximal sp1 ))) where -- x < f x |
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563 sp1 : SUP A (ZChain.chain zc) |
703 | 564 sp1 = sp0 (cf nmx) (cf-is-≤-monotonic nmx) zc total |
538 | 565 c = & (SUP.sup sp1) |
548 | 566 |
757 | 567 uchain : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) → HOD |
568 uchain f mf {y} ay = record { od = record { def = λ x → FClosure A f y x } ; odmax = & A ; <odmax = | |
569 λ {z} cz → subst (λ k → k o< & A) &iso ( c<→o< (subst (λ k → odef A k ) (sym &iso ) (A∋fc y f mf cz ))) } | |
570 | |
571 utotal : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) | |
572 → IsTotalOrderSet (uchain f mf ay) | |
573 utotal f mf {y} ay {a} {b} ca cb = subst₂ (λ j k → Tri (j < k) (j ≡ k) (k < j)) *iso *iso uz01 where | |
574 uz01 : Tri (* (& a) < * (& b)) (* (& a) ≡ * (& b)) (* (& b) < * (& a) ) | |
575 uz01 = fcn-cmp y f mf ca cb | |
576 | |
577 ysup : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) | |
578 → SUP A (uchain f mf ay) | |
579 ysup f mf {y} ay = supP (uchain f mf ay) (λ lt → A∋fc y f mf lt) (utotal f mf ay) | |
580 | |
711 | 581 inititalChain : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) → ZChain A f mf ay o∅ |
756 | 582 inititalChain f mf {y} ay = record { supf = isupf ; chain⊆A = λ lt → proj1 lt ; chain∋init = cy ; csupf = ? ; fcy<sup = ? |
745 | 583 ; initial = isy ; f-next = inext ; f-total = itotal ; sup=u = λ b<0 → ⊥-elim (¬x<0 b<0) ; order = λ b<0 → ⊥-elim (¬x<0 b<0) } where |
711 | 584 isupf : Ordinal → Ordinal |
757 | 585 isupf z = & (SUP.sup (ysup f mf ay)) |
711 | 586 cy : odef (UnionCF A f mf ay isupf o∅) y |
750 | 587 cy = ⟪ ay , ch-init (init ay) ⟫ |
711 | 588 isy : {z : Ordinal } → odef (UnionCF A f mf ay isupf o∅) z → * y ≤ * z |
748 | 589 isy {z} ⟪ az , uz ⟫ with uz |
590 ... | ch-init fc = s≤fc y f mf fc | |
757 | 591 ... | ch-is-sup u u≤x is-sup fc = ⊥-elim ( <-irr (case1 refl) ? ) |
711 | 592 inext : {a : Ordinal} → odef (UnionCF A f mf ay isupf o∅) a → odef (UnionCF A f mf ay isupf o∅) (f a) |
748 | 593 inext {a} ua with (proj2 ua) |
594 ... | ch-init fc = ⟪ proj2 (mf _ (proj1 ua)) , ch-init (fsuc _ fc ) ⟫ | |
757 | 595 ... | ch-is-sup u u≤x is-sup fc = ⊥-elim ( <-irr (case1 refl) ? ) |
711 | 596 itotal : IsTotalOrderSet (UnionCF A f mf ay isupf o∅) |
597 itotal {a} {b} ca cb = subst₂ (λ j k → Tri (j < k) (j ≡ k) (k < j)) *iso *iso uz01 where | |
598 uz01 : Tri (* (& a) < * (& b)) (* (& a) ≡ * (& b)) (* (& b) < * (& a) ) | |
748 | 599 uz01 = chain-total A f mf ay isupf (proj2 ca) (proj2 cb) |
711 | 600 imax : {a b : Ordinal} → odef (UnionCF A f mf ay isupf o∅) a → |
712 | 601 b o< o∅ → (ab : odef A b) → |
711 | 602 HasPrev A (UnionCF A f mf ay isupf o∅) ab f ∨ IsSup A (UnionCF A f mf ay isupf o∅) ab → |
603 * a < * b → odef (UnionCF A f mf ay isupf o∅) b | |
714 | 604 imax {a} {b} ua b<x ab (case1 hasp) a<b = subst (λ k → odef (UnionCF A f mf ay isupf o∅) k ) (sym (HasPrev.x=fy hasp)) ( inext (HasPrev.ay hasp) ) |
605 imax {a} {b} ua b<x ab (case2 sup) a<b = ⊥-elim ( ¬x<0 b<x ) | |
711 | 606 |
560 | 607 -- |
547 | 608 -- create all ZChains under o< x |
560 | 609 -- |
608
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610 |
674 | 611 ind : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) {y : Ordinal} (ay : odef A y) → (x : Ordinal) |
703 | 612 → ((z : Ordinal) → z o< x → ZChain A f mf ay z) → ZChain A f mf ay x |
707 | 613 ind f mf {y} ay x prev with Oprev-p x |
697 | 614 ... | yes op = zc4 where |
682 | 615 -- |
616 -- we have previous ordinal to use induction | |
617 -- | |
618 px = Oprev.oprev op | |
703 | 619 zc : ZChain A f mf ay (Oprev.oprev op) |
682 | 620 zc = prev px (subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc ) |
621 px<x : px o< x | |
622 px<x = subst (λ k → px o< k) (Oprev.oprev=x op) <-osuc | |
709 | 623 zc-b<x : (b : Ordinal ) → b o< x → b o< osuc px |
624 zc-b<x b lt = subst (λ k → b o< k ) (sym (Oprev.oprev=x op)) lt | |
697 | 625 |
703 | 626 pchain : HOD |
627 pchain = UnionCF A f mf ay (ZChain.supf zc) x | |
628 ptotal : IsTotalOrderSet pchain | |
629 ptotal {a} {b} ca cb = subst₂ (λ j k → Tri (j < k) (j ≡ k) (k < j)) *iso *iso uz01 where | |
630 uz01 : Tri (* (& a) < * (& b)) (* (& a) ≡ * (& b)) (* (& b) < * (& a) ) | |
748 | 631 uz01 = chain-total A f mf ay (ZChain.supf zc) ( (proj2 ca)) ( (proj2 cb)) |
704 | 632 pchain⊆A : {y : Ordinal} → odef pchain y → odef A y |
633 pchain⊆A {y} ny = proj1 ny | |
634 pnext : {a : Ordinal} → odef pchain a → odef pchain (f a) | |
749 | 635 pnext {a} ⟪ aa , ch-init fc ⟫ = ⟪ proj2 (mf a aa) , ch-init (fsuc _ fc) ⟫ |
756 | 636 pnext {a} ⟪ aa , ch-is-sup u u≤x is-sup fc ⟫ = ⟪ proj2 (mf a aa) , ch-is-sup u u≤x (ChainP-next A f mf ay _ is-sup ) (fsuc _ fc ) ⟫ |
704 | 637 pinit : {y₁ : Ordinal} → odef pchain y₁ → * y ≤ * y₁ |
748 | 638 pinit {a} ⟪ aa , ua ⟫ with ua |
639 ... | ch-init fc = s≤fc y f mf fc | |
756 | 640 ... | ch-is-sup u u≤x is-sup fc = ≤-ftrans (case2 zc7) (s≤fc _ f mf fc) where |
749 | 641 zc7 : y << (ZChain.supf zc) u |
707 | 642 zc7 = ChainP.fcy<sup is-sup (init ay) |
704 | 643 pcy : odef pchain y |
748 | 644 pcy = ⟪ ay , ch-init (init ay) ⟫ |
703 | 645 |
754 | 646 supf0 = ZChain.supf zc |
647 | |
648 csupf : {z : Ordinal} → odef (UnionCF A f mf ay supf0 x) (supf0 z) | |
649 csupf {z} with ZChain.csupf zc {z} | |
650 ... | ⟪ az , ch-init fc ⟫ = ⟪ az , ch-init fc ⟫ | |
756 | 651 ... | ⟪ az , ch-is-sup u u<px is-sup fc ⟫ = ⟪ az , ch-is-sup u (OrdTrans u<px (o<→≤ px<x)) is-sup fc ⟫ |
745 | 652 |
611 | 653 -- if previous chain satisfies maximality, we caan reuse it |
654 -- | |
727 | 655 no-extension : ZChain A f mf ay x |
745 | 656 no-extension = record { supf = supf0 |
756 | 657 ; initial = pinit ; chain∋init = pcy ; csupf = csupf ; sup=f = ? ; order = ? ; fcy<sup = ? |
754 | 658 ; chain⊆A = pchain⊆A ; f-next = pnext ; f-total = ptotal } |
709 | 659 |
703 | 660 zc4 : ZChain A f mf ay x |
713 | 661 zc4 with ODC.∋-p O A (* px) |
727 | 662 ... | no noapx = no-extension -- ¬ A ∋ p, just skip |
713 | 663 ... | yes apx with ODC.p∨¬p O ( HasPrev A (ZChain.chain zc ) apx f ) |
703 | 664 -- we have to check adding x preserve is-max ZChain A y f mf x |
727 | 665 ... | case1 pr = no-extension -- we have previous A ∋ z < x , f z ≡ x, so chain ∋ f z ≡ x because of f-next |
713 | 666 ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A (ZChain.chain zc ) apx ) |
682 | 667 ... | case1 is-sup = -- x is a sup of zc |
756 | 668 record { supf = psupf1 ; chain⊆A = ? ; f-next = ? ; f-total = ? ; csupf = ? ; sup=f = ? ; order = ? ; fcy<sup = ? |
754 | 669 ; initial = ? ; chain∋init = ? } where |
750 | 670 psupf1 : Ordinal → Ordinal |
671 psupf1 z with trio< z x | |
672 ... | tri< a ¬b ¬c = ZChain.supf zc z | |
673 ... | tri≈ ¬a b ¬c = x | |
674 ... | tri> ¬a ¬b c = x | |
727 | 675 ... | case2 ¬x=sup = no-extension -- px is not f y' nor sup of former ZChain from y -- no extention |
728 | 676 ... | no lim = zc5 where |
726
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psupf-mono and is-max conflict
Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
725
diff
changeset
|
677 |
703 | 678 pzc : (z : Ordinal) → z o< x → ZChain A f mf ay z |
679 pzc z z<x = prev z z<x | |
726
b2e2cd12e38f
psupf-mono and is-max conflict
Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
725
diff
changeset
|
680 |
703 | 681 psupf0 : (z : Ordinal) → Ordinal |
682 psupf0 z with trio< z x | |
755 | 683 ... | tri< a ¬b ¬c = ZChain.supf (pzc (osuc z) (ob<x lim a)) z |
684 ... | tri≈ ¬a b ¬c = & A -- Sup of FClosure A f y z ? | |
685 ... | tri> ¬a ¬b c = & A -- | |
686 | |
687 pchain0 : HOD | |
688 pchain0 = UnionCF A f mf ay psupf0 x | |
689 | |
690 ptotal0 : IsTotalOrderSet pchain0 | |
691 ptotal0 {a} {b} ca cb = subst₂ (λ j k → Tri (j < k) (j ≡ k) (k < j)) *iso *iso uz01 where | |
692 uz01 : Tri (* (& a) < * (& b)) (* (& a) ≡ * (& b)) (* (& b) < * (& a) ) | |
693 uz01 = chain-total A f mf ay psupf0 ( (proj2 ca)) ( (proj2 cb)) | |
694 | |
695 | |
696 usup : SUP A pchain0 | |
697 usup = supP pchain0 (λ lt → proj1 lt) ptotal0 | |
698 spu = & (SUP.sup usup) | |
699 | |
700 psupf : Ordinal → Ordinal | |
701 psupf z with trio< z x | |
702 ... | tri< a ¬b ¬c = ZChain.supf (pzc (osuc z) (ob<x lim a)) z | |
703 ... | tri≈ ¬a b ¬c = spu | |
704 ... | tri> ¬a ¬b c = spu | |
705 | |
706 psupf>z : {z : Ordinal } → x o< z → spu ≡ psupf z | |
707 psupf>z {z} x<z with trio< z x | |
708 ... | tri< a ¬b ¬c = ⊥-elim ( ¬c x<z) | |
709 ... | tri≈ ¬a b ¬c = ⊥-elim ( ¬c x<z) | |
710 ... | tri> ¬a ¬b c = refl | |
711 | |
712 psupf=x : spu ≡ psupf x | |
713 psupf=x = zc20 refl where | |
714 zc20 : {z : Ordinal } → z ≡ x → spu ≡ psupf x | |
715 zc20 {z} z=x with trio< z x | inspect psupf z | |
716 ... | tri< a ¬b ¬c | _ = ⊥-elim ( ¬b z=x) | |
717 ... | tri≈ ¬a b ¬c | record { eq = eq1 } = subst (λ k → spu ≡ psupf k) b (sym eq1) | |
718 ... | tri> ¬a ¬b c | _ = ⊥-elim ( ¬b z=x) | |
719 | |
720 csupf :{z : Ordinal} → odef (UnionCF A f mf ay psupf x) (psupf z) | |
721 csupf {z} with trio< z x | inspect psupf z | |
722 ... | tri< z<x ¬b ¬c | record { eq = eq1 } = zc11 where | |
723 ozc = pzc (osuc z) (ob<x lim z<x) | |
724 zc12 : odef A (ZChain.supf ozc z) | |
725 ∧ UChain A f mf ay (ZChain.supf ozc) (osuc z) (ZChain.supf ozc z) | |
726 zc12 = ZChain.csupf ozc {z} | |
727 zc11 : odef A (ZChain.supf ozc z) ∧ UChain A f mf ay psupf x (ZChain.supf ozc z) | |
728 zc11 with zc12 | |
729 ... | ⟪ az , ch-init fc ⟫ = ⟪ az , ch-init fc ⟫ | |
730 ... | ⟪ az , ch-is-sup u u<z is-sup fc ⟫ = ⟪ az , ch-is-sup z (o<→≤ z<x) | |
731 zc14 (subst (λ k → FClosure A f k (ZChain.supf ozc z)) (sym eq1) (init az)) ⟫ where | |
732 zc14 : ChainP A f mf ay psupf z (ZChain.supf ozc z) | |
733 zc14 = ? | |
734 ... | tri≈ ¬a b ¬c | record { eq = eq1 } = ⟪ SUP.A∋maximal usup , ch-is-sup x <-osuc zc15 | |
735 (subst (λ k → FClosure A f k spu) zc17 (init (SUP.A∋maximal usup))) ⟫ where | |
736 zc15 : ChainP A f mf ay psupf x spu | |
737 zc15 = ? | |
738 zc17 : spu ≡ psupf x | |
739 zc17 = subst (λ k → spu ≡ psupf k ) b (sym eq1) | |
740 ... | tri> ¬a ¬b c | record { eq = eq1 } = ⟪ SUP.A∋maximal usup , ch-is-sup x <-osuc zc16 | |
741 (subst (λ k → FClosure A f k spu) psupf=x (init (SUP.A∋maximal usup))) ⟫ where | |
742 zc16 : ChainP A f mf ay psupf x spu | |
743 zc16 = ? | |
726
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Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
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|
744 |
704 | 745 pchain : HOD |
755 | 746 pchain = UnionCF A f mf ay psupf x |
704 | 747 |
748 pchain⊆A : {y : Ordinal} → odef pchain y → odef A y | |
749 pchain⊆A {y} ny = proj1 ny | |
750 pnext : {a : Ordinal} → odef pchain a → odef pchain (f a) | |
750 | 751 pnext {a} ⟪ aa , ch-init fc ⟫ = ⟪ proj2 ( mf a aa ) , ch-init (fsuc _ fc) ⟫ |
756 | 752 pnext {a} ⟪ aa , ch-is-sup u u≤x is-sup fc ⟫ = ⟪ proj2 ( mf a aa ) , ch-is-sup u u≤x (ChainP-next A f mf ay _ is-sup ) (fsuc _ fc) ⟫ |
704 | 753 pinit : {y₁ : Ordinal} → odef pchain y₁ → * y ≤ * y₁ |
748 | 754 pinit {a} ⟪ aa , ua ⟫ with ua |
755 ... | ch-init fc = s≤fc y f mf fc | |
756 | 756 ... | ch-is-sup u u≤x is-sup fc = ≤-ftrans (case2 zc7) (s≤fc _ f mf fc) where |
755 | 757 zc7 : y << psupf ? |
707 | 758 zc7 = ChainP.fcy<sup is-sup (init ay) |
704 | 759 pcy : odef pchain y |
748 | 760 pcy = ⟪ ay , ch-init (init ay) ⟫ |
755 | 761 ptotal : IsTotalOrderSet pchain |
762 ptotal {a} {b} ca cb = subst₂ (λ j k → Tri (j < k) (j ≡ k) (k < j)) *iso *iso uz01 where | |
763 uz01 : Tri (* (& a) < * (& b)) (* (& a) ≡ * (& b)) (* (& b) < * (& a) ) | |
764 uz01 = chain-total A f mf ay psupf ( (proj2 ca)) ( (proj2 cb)) | |
754 | 765 |
766 no-extension : ZChain A f mf ay x | |
756 | 767 no-extension = record { initial = pinit ; chain∋init = pcy ; supf = psupf ; csupf = csupf ; sup=u = ? ; order = ? ; fcy<sup = ? |
755 | 768 ; chain⊆A = pchain⊆A ; f-next = pnext ; f-total = ptotal } |
754 | 769 |
703 | 770 zc5 : ZChain A f mf ay x |
697 | 771 zc5 with ODC.∋-p O A (* x) |
732
ddeb107b6f71
bchain can be reached from upwords by f. so it is worng.
Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
729
diff
changeset
|
772 ... | no noax = no-extension -- ¬ A ∋ p, just skip |
704 | 773 ... | yes ax with ODC.p∨¬p O ( HasPrev A pchain ax f ) |
703 | 774 -- we have to check adding x preserve is-max ZChain A y f mf x |
727 | 775 ... | case1 pr = no-extension |
704 | 776 ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A pchain ax ) |
756 | 777 ... | case1 is-sup = record { initial = {!!} ; chain∋init = {!!} ; supf = psupf1 ; csupf = ? ; sup=u = ? ; order = ? ; fcy<sup = ? |
739 | 778 ; chain⊆A = {!!} ; f-next = {!!} ; f-total = ? } where -- x is a sup of (zc ?) |
728 | 779 psupf1 : Ordinal → Ordinal |
780 psupf1 z with trio< z x | |
781 ... | tri< a ¬b ¬c = ZChain.supf (pzc z a) z | |
782 ... | tri≈ ¬a b ¬c = x | |
783 ... | tri> ¬a ¬b c = x | |
727 | 784 ... | case2 ¬x=sup = no-extension -- x is not f y' nor sup of former ZChain from y -- no extention |
553 | 785 |
703 | 786 SZ : ( f : Ordinal → Ordinal ) → (mf : ≤-monotonic-f A f ) → {y : Ordinal} (ay : odef A y) → ZChain A f mf ay (& A) |
787 SZ f mf {y} ay = TransFinite {λ z → ZChain A f mf ay z } (λ x → ind f mf ay x ) (& A) | |
608
6655f03984f9
mutual tranfinite in zorn
Shinji KONO <kono@ie.u-ryukyu.ac.jp>
parents:
607
diff
changeset
|
788 |
551 | 789 zorn00 : Maximal A |
790 zorn00 with is-o∅ ( & HasMaximal ) -- we have no Level (suc n) LEM | |
791 ... | no not = record { maximal = ODC.minimal O HasMaximal (λ eq → not (=od∅→≡o∅ eq)) ; A∋maximal = zorn01 ; ¬maximal<x = zorn02 } where | |
792 -- yes we have the maximal | |
793 zorn03 : odef HasMaximal ( & ( ODC.minimal O HasMaximal (λ eq → not (=od∅→≡o∅ eq)) ) ) | |
606 | 794 zorn03 = ODC.x∋minimal O HasMaximal (λ eq → not (=od∅→≡o∅ eq)) -- Axiom of choice |
551 | 795 zorn01 : A ∋ ODC.minimal O HasMaximal (λ eq → not (=od∅→≡o∅ eq)) |
796 zorn01 = proj1 zorn03 | |
797 zorn02 : {x : HOD} → A ∋ x → ¬ (ODC.minimal O HasMaximal (λ eq → not (=od∅→≡o∅ eq)) < x) | |
798 zorn02 {x} ax m<x = proj2 zorn03 (& x) ax (subst₂ (λ j k → j < k) (sym *iso) (sym *iso) m<x ) | |
703 | 799 ... | yes ¬Maximal = ⊥-elim ( z04 nmx zorn04 total ) where |
551 | 800 -- if we have no maximal, make ZChain, which contradict SUP condition |
801 nmx : ¬ Maximal A | |
802 nmx mx = ∅< {HasMaximal} zc5 ( ≡o∅→=od∅ ¬Maximal ) where | |
803 zc5 : odef A (& (Maximal.maximal mx)) ∧ (( y : Ordinal ) → odef A y → ¬ (* (& (Maximal.maximal mx)) < * y)) | |
804 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) ) ⟫ | |
703 | 805 zorn04 : ZChain A (cf nmx) (cf-is-≤-monotonic nmx) as0 (& A) |
653 | 806 zorn04 = SZ (cf nmx) (cf-is-≤-monotonic nmx) (subst (λ k → odef A k ) &iso as ) |
634 | 807 total : IsTotalOrderSet (ZChain.chain zorn04) |
654 | 808 total {a} {b} = zorn06 where |
809 zorn06 : odef (ZChain.chain zorn04) (& a) → odef (ZChain.chain zorn04) (& b) → Tri (a < b) (a ≡ b) (b < a) | |
810 zorn06 = ZChain.f-total (SZ (cf nmx) (cf-is-≤-monotonic nmx) (subst (λ k → odef A k ) &iso as) ) | |
551 | 811 |
516 | 812 -- usage (see filter.agda ) |
813 -- | |
497 | 814 -- _⊆'_ : ( A B : HOD ) → Set n |
815 -- _⊆'_ A B = (x : Ordinal ) → odef A x → odef B x | |
482 | 816 |
497 | 817 -- MaximumSubset : {L P : HOD} |
818 -- → o∅ o< & L → o∅ o< & P → P ⊆ L | |
819 -- → IsPartialOrderSet P _⊆'_ | |
820 -- → ( (B : HOD) → B ⊆ P → IsTotalOrderSet B _⊆'_ → SUP P B _⊆'_ ) | |
821 -- → Maximal P (_⊆'_) | |
822 -- MaximumSubset {L} {P} 0<L 0<P P⊆L PO SP = Zorn-lemma {P} {_⊆'_} 0<P PO SP |