comparison src/zorn.agda @ 570:c642cbafc07a

...
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Mon, 02 May 2022 12:43:42 +0900
parents 33b1ade17f83
children 2ade91846f57
comparison
equal deleted inserted replaced
569:33b1ade17f83 570:c642cbafc07a
52 52
53 -- 53 --
54 -- Partial Order on HOD ( possibly limited in A ) 54 -- Partial Order on HOD ( possibly limited in A )
55 -- 55 --
56 56
57 _<<_ : (x y : Ordinal ) → Set n
58 x << y = * x < * y
59
60 POO : IsStrictPartialOrder _≡_ _<<_
61 POO = record { isEquivalence = record { refl = refl ; sym = sym ; trans = trans }
62 ; trans = IsStrictPartialOrder.trans PO
63 ; irrefl = λ x=y x<y → IsStrictPartialOrder.irrefl PO (cong (*) x=y) x<y
64 ; <-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 } }
65
57 _≤_ : (x y : HOD) → Set (Level.suc n) 66 _≤_ : (x y : HOD) → Set (Level.suc n)
58 x ≤ y = ( x ≡ y ) ∨ ( x < y ) 67 x ≤ y = ( x ≡ y ) ∨ ( x < y )
59 68
60 ≤-ftrans : {x y z : HOD} → x ≤ y → y ≤ z → x ≤ z 69 ≤-ftrans : {x y z : HOD} → x ≤ y → y ≤ z → x ≤ z
61 ≤-ftrans {x} {y} {z} (case1 refl ) (case1 refl ) = case1 refl 70 ≤-ftrans {x} {y} {z} (case1 refl ) (case1 refl ) = case1 refl
220 field 229 field
221 y : Ordinal 230 y : Ordinal
222 ay : odef B y 231 ay : odef B y
223 x=fy : x ≡ f y 232 x=fy : x ≡ f y
224 233
225 record IsSup (A B : HOD) (T : IsTotalOrderSet B) ( B⊆A : B ⊆' A ) 234 record IsSup (A B : HOD) {x : Ordinal } (xa : odef A x) : Set n where
226 {x : Ordinal } (xa : odef A x) (sup : (C : HOD ) → ( C ⊆' A) → IsTotalOrderSet C → Ordinal) ( f : Ordinal → Ordinal ) : Set n where
227 field 235 field
228 chain : Ordinal 236 chain : Ordinal
229 chain⊆B : (* chain) ⊆' B 237 chain⊆B : (* chain) ⊆' B
230 x=sup : x ≡ sup (* chain) ( λ lt → B⊆A (chain⊆B lt ) ) 238 x<sup : {y : Ordinal} → odef (* chain) y → (y ≡ x ) ∨ (y << x )
231 ( ⊆-IsTotalOrderSet {B} {* chain} record { incl = chain⊆B } T )
232 -- ¬prev : ¬ HasPrev A (* chain) xa f
233 239
234 record ZChain ( A : HOD ) {x : Ordinal} (ax : odef A x) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f ) 240 record ZChain ( A : HOD ) {x : Ordinal} (ax : odef A x) ( f : Ordinal → Ordinal ) (mf : ≤-monotonic-f A f )
235 (sup : (C : HOD ) → ( C ⊆' A) → IsTotalOrderSet C → Ordinal) ( z : Ordinal ) : Set (Level.suc n) where 241 (sup : (C : HOD ) → ( C ⊆' A) → IsTotalOrderSet C → Ordinal) ( z : Ordinal ) : Set (Level.suc n) where
236 field 242 field
237 chain : HOD 243 chain : HOD
240 initial : {y : Ordinal } → odef chain y → * x ≤ * y 246 initial : {y : Ordinal } → odef chain y → * x ≤ * y
241 f-total : IsTotalOrderSet chain 247 f-total : IsTotalOrderSet chain
242 f-next : {a : Ordinal } → odef chain a → odef chain (f a) 248 f-next : {a : Ordinal } → odef chain a → odef chain (f a)
243 f-immediate : { x y : Ordinal } → odef chain x → odef chain y → ¬ ( ( * x < * y ) ∧ ( * y < * (f x )) ) 249 f-immediate : { x y : Ordinal } → odef chain x → odef chain y → ¬ ( ( * x < * y ) ∧ ( * y < * (f x )) )
244 is-max : {a b : Ordinal } → (ca : odef chain a ) → b o< osuc z → (ab : odef A b) 250 is-max : {a b : Ordinal } → (ca : odef chain a ) → b o< osuc z → (ab : odef A b)
245 → HasPrev A chain ab f ∨ IsSup A chain f-total chain⊆A ab sup f -- ((sup chain chain⊆A f-total) ≡ b ) 251 → HasPrev A chain ab f ∨ IsSup A chain ab -- ((sup chain chain⊆A f-total) ≡ b )
246 → * a < * b → odef chain b 252 → * a < * b → odef chain b
247 253
248 record Maximal ( A : HOD ) : Set (Level.suc n) where 254 record Maximal ( A : HOD ) : Set (Level.suc n) where
249 field 255 field
250 maximal : HOD 256 maximal : HOD
331 → f (& (SUP.sup (sp0 f mf zc ))) ≡ & (SUP.sup (sp0 f mf zc )) 337 → f (& (SUP.sup (sp0 f mf zc ))) ≡ & (SUP.sup (sp0 f mf zc ))
332 z03 f mf zc = z14 where 338 z03 f mf zc = z14 where
333 chain = ZChain.chain zc 339 chain = ZChain.chain zc
334 sp1 = sp0 f mf zc 340 sp1 = sp0 f mf zc
335 z10 : {a b : Ordinal } → (ca : odef chain a ) → b o< osuc (& A) → (ab : odef A b ) 341 z10 : {a b : Ordinal } → (ca : odef chain a ) → b o< osuc (& A) → (ab : odef A b )
336 → HasPrev A chain ab f ∨ IsSup A chain (ZChain.f-total zc) (ZChain.chain⊆A zc) {b} ab supO f -- (supO chain (ZChain.chain⊆A zc) (ZChain.f-total zc) ≡ b ) 342 → HasPrev A chain ab f ∨ IsSup A chain {b} ab -- (supO chain (ZChain.chain⊆A zc) (ZChain.f-total zc) ≡ b )
337 → * a < * b → odef chain b 343 → * a < * b → odef chain b
338 z10 = ZChain.is-max zc 344 z10 = ZChain.is-max zc
339 z11 : & (SUP.sup sp1) o< & A 345 z11 : & (SUP.sup sp1) o< & A
340 z11 = c<→o< ( SUP.A∋maximal sp1) 346 z11 = c<→o< ( SUP.A∋maximal sp1)
341 z12 : odef chain (& (SUP.sup sp1)) 347 z12 : odef chain (& (SUP.sup sp1))
342 z12 with o≡? (& s) (& (SUP.sup sp1)) 348 z12 with o≡? (& s) (& (SUP.sup sp1))
343 ... | yes eq = subst (λ k → odef chain k) eq ( ZChain.chain∋x zc ) 349 ... | yes eq = subst (λ k → odef chain k) eq ( ZChain.chain∋x zc )
344 ... | no ne = z10 {& s} {& (SUP.sup sp1)} ( ZChain.chain∋x zc ) (ordtrans z11 <-osuc ) (SUP.A∋maximal sp1) 350 ... | no ne = z10 {& s} {& (SUP.sup sp1)} ( ZChain.chain∋x zc ) (ordtrans z11 <-osuc ) (SUP.A∋maximal sp1)
345 (case2 record { chain = & chain ; chain⊆B = λ z → subst (λ k → odef k _ ) *iso z ; x=sup = cong (&) (sup== (sym *iso)) } ) z13 where 351 (case2 z19 ) z13 where
346 z13 : * (& s) < * (& (SUP.sup sp1)) 352 z13 : * (& s) < * (& (SUP.sup sp1))
347 z13 with SUP.x<sup sp1 ( ZChain.chain∋x zc ) 353 z13 with SUP.x<sup sp1 ( ZChain.chain∋x zc )
348 ... | case1 eq = ⊥-elim ( ne (cong (&) eq) ) 354 ... | case1 eq = ⊥-elim ( ne (cong (&) eq) )
349 ... | case2 lt = subst₂ (λ j k → j < k ) (sym *iso) (sym *iso) lt 355 ... | case2 lt = subst₂ (λ j k → j < k ) (sym *iso) (sym *iso) lt
356 z19 : IsSup A chain {& (SUP.sup sp1)} (SUP.A∋maximal sp1)
357 z19 = record { chain = & chain ; chain⊆B = λ z → subst (λ k → odef k _ ) *iso z ; x<sup = z20 } where
358 z20 : {y : Ordinal} → odef (* (& chain)) y → (y ≡ & (SUP.sup sp1)) ∨ (y << & (SUP.sup sp1))
359 z20 {y} zy with SUP.x<sup sp1 (subst₂ (λ j k → odef j k ) *iso (sym &iso) zy)
360 ... | case1 y=p = case1 (subst (λ k → k ≡ _ ) &iso ( cong (&) y=p ))
361 ... | case2 y<p = case2 (subst (λ k → * y < k ) (sym *iso) y<p )
362 -- λ {y} zy → subst (λ k → (y ≡ & k ) ∨ (y << & k)) ? (SUP.x<sup sp1 ? ) }
350 z14 : f (& (SUP.sup (sp0 f mf zc))) ≡ & (SUP.sup (sp0 f mf zc)) 363 z14 : f (& (SUP.sup (sp0 f mf zc))) ≡ & (SUP.sup (sp0 f mf zc))
351 z14 with ZChain.f-total zc (subst (λ k → odef chain k) (sym &iso) (ZChain.f-next zc z12 )) z12 364 z14 with ZChain.f-total zc (subst (λ k → odef chain k) (sym &iso) (ZChain.f-next zc z12 )) z12
352 ... | tri< a ¬b ¬c = ⊥-elim z16 where 365 ... | tri< a ¬b ¬c = ⊥-elim z16 where
353 z16 : ⊥ 366 z16 : ⊥
354 z16 with proj1 (mf (& ( SUP.sup sp1)) ( SUP.A∋maximal sp1 )) 367 z16 with proj1 (mf (& ( SUP.sup sp1)) ( SUP.A∋maximal sp1 ))
397 ... | no noax = -- ¬ A ∋ p, just skip 410 ... | no noax = -- ¬ A ∋ p, just skip
398 record { chain = ZChain.chain zc0 ; chain⊆A = ZChain.chain⊆A zc0 ; initial = ZChain.initial zc0 411 record { chain = ZChain.chain zc0 ; chain⊆A = ZChain.chain⊆A zc0 ; initial = ZChain.initial zc0
399 ; f-total = ZChain.f-total zc0 ; f-next = ZChain.f-next zc0 412 ; f-total = ZChain.f-total zc0 ; f-next = ZChain.f-next zc0
400 ; f-immediate = ZChain.f-immediate zc0 ; chain∋x = ZChain.chain∋x zc0 ; is-max = zc11 } where -- no extention 413 ; f-immediate = ZChain.f-immediate zc0 ; chain∋x = ZChain.chain∋x zc0 ; is-max = zc11 } where -- no extention
401 zc11 : {a b : Ordinal} → odef (ZChain.chain zc0) a → b o< osuc x → (ab : odef A b) → 414 zc11 : {a b : Ordinal} → odef (ZChain.chain zc0) a → b o< osuc x → (ab : odef A b) →
402 HasPrev A (ZChain.chain zc0) ab f ∨ IsSup A (ZChain.chain zc0) (ZChain.f-total zc0) (ZChain.chain⊆A zc0) ab supO f → 415 HasPrev A (ZChain.chain zc0) ab f ∨ IsSup A (ZChain.chain zc0) ab →
403 * a < * b → odef (ZChain.chain zc0) b 416 * a < * b → odef (ZChain.chain zc0) b
404 zc11 {a} {b} za b<ox ab P a<b with osuc-≡< b<ox 417 zc11 {a} {b} za b<ox ab P a<b with osuc-≡< b<ox
405 ... | case1 eq = ⊥-elim ( noax (subst (λ k → odef A k) (trans eq (sym &iso)) ab ) ) 418 ... | case1 eq = ⊥-elim ( noax (subst (λ k → odef A k) (trans eq (sym &iso)) ab ) )
406 ... | case2 lt = ZChain.is-max zc0 za (zc0-b<x b lt) ab P a<b 419 ... | case2 lt = ZChain.is-max zc0 za (zc0-b<x b lt) ab P a<b
407 ... | yes ax with ODC.p∨¬p O ( HasPrev A (ZChain.chain zc0) ax f ) -- we have to check adding x preserve is-max ZChain A ay f mf supO x 420 ... | yes ax with ODC.p∨¬p O ( HasPrev A (ZChain.chain zc0) ax f ) -- we have to check adding x preserve is-max ZChain A ay f mf supO x
408 ... | case1 pr = zc9 where -- we have previous A ∋ z < x , f z ≡ x, so chain ∋ f z ≡ x because of f-next 421 ... | case1 pr = zc9 where -- we have previous A ∋ z < x , f z ≡ x, so chain ∋ f z ≡ x because of f-next
409 chain = ZChain.chain zc0 422 chain = ZChain.chain zc0
410 zc17 : {a b : Ordinal} → odef (ZChain.chain zc0) a → b o< osuc x → (ab : odef A b) → 423 zc17 : {a b : Ordinal} → odef (ZChain.chain zc0) a → b o< osuc x → (ab : odef A b) →
411 HasPrev A (ZChain.chain zc0) ab f ∨ IsSup A (ZChain.chain zc0) (ZChain.f-total zc0) (ZChain.chain⊆A zc0) ab supO f → 424 HasPrev A (ZChain.chain zc0) ab f ∨ IsSup A (ZChain.chain zc0) ab →
412 * a < * b → odef (ZChain.chain zc0) b 425 * a < * b → odef (ZChain.chain zc0) b
413 zc17 {a} {b} za b<ox ab P a<b with osuc-≡< b<ox 426 zc17 {a} {b} za b<ox ab P a<b with osuc-≡< b<ox
414 ... | case2 lt = ZChain.is-max zc0 za (zc0-b<x b lt) ab P a<b 427 ... | case2 lt = ZChain.is-max zc0 za (zc0-b<x b lt) ab P a<b
415 ... | case1 b=x = subst (λ k → odef chain k ) (trans (sym (HasPrev.x=fy pr )) (trans &iso (sym b=x)) ) ( ZChain.f-next zc0 (HasPrev.ay pr)) 428 ... | case1 b=x = subst (λ k → odef chain k ) (trans (sym (HasPrev.x=fy pr )) (trans &iso (sym b=x)) ) ( ZChain.f-next zc0 (HasPrev.ay pr))
416 zc9 : ZChain A ay f mf supO x 429 zc9 : ZChain A ay f mf supO x
417 zc9 = record { chain = ZChain.chain zc0 ; chain⊆A = ZChain.chain⊆A zc0 ; f-total = ZChain.f-total zc0 ; f-next = ZChain.f-next zc0 430 zc9 = record { chain = ZChain.chain zc0 ; chain⊆A = ZChain.chain⊆A zc0 ; f-total = ZChain.f-total zc0 ; f-next = ZChain.f-next zc0
418 ; initial = ZChain.initial zc0 ; f-immediate = ZChain.f-immediate zc0 ; chain∋x = ZChain.chain∋x zc0 ; is-max = zc17 } -- no extention 431 ; initial = ZChain.initial zc0 ; f-immediate = ZChain.f-immediate zc0 ; chain∋x = ZChain.chain∋x zc0 ; is-max = zc17 } -- no extention
419 ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A (ZChain.chain zc0) (ZChain.f-total zc0) (ZChain.chain⊆A zc0) ax supO f) 432 ... | case2 ¬fy<x with ODC.p∨¬p O (IsSup A (ZChain.chain zc0) ax )
420 ... | case1 x=sup = -- previous ordinal is a sup of a smaller ZChain 433 ... | case1 is-sup = -- previous ordinal is a sup of a smaller ZChain
421 record { chain = schain ; chain⊆A = s⊆A ; f-total = scmp ; f-next = scnext 434 record { chain = schain ; chain⊆A = s⊆A ; f-total = scmp ; f-next = scnext
422 ; initial = scinit ; f-immediate = simm ; chain∋x = case1 (ZChain.chain∋x zc0) ; is-max = {!!} } where -- x is sup 435 ; initial = scinit ; f-immediate = simm ; chain∋x = case1 (ZChain.chain∋x zc0) ; is-max = s-ismax } where -- x is sup
423 sup0 = supP ( ZChain.chain zc0 ) (ZChain.chain⊆A zc0 ) (ZChain.f-total zc0) 436 -- sup0 = supP ( ZChain.chain zc0 ) (ZChain.chain⊆A zc0 ) (ZChain.f-total zc0)
437 -- sp = SUP.sup sup0
438 -- x=sup : IsSup A (ZChain.chain zc0) {& (* x)} ax → x ≡ & sp -- sup is not minimum, so this may wrong
439 sup0 : SUP A (ZChain.chain zc0)
440 sup0 = record { sup = * x ; A∋maximal = ax ; x<sup = {!!} }
441 sp : HOD
424 sp = SUP.sup sup0 442 sp = SUP.sup sup0
443 x=sup : x ≡ & sp
444 x=sup = sym &iso
425 chain = ZChain.chain zc0 445 chain = ZChain.chain zc0
426 sc<A : {y : Ordinal} → odef chain y ∨ FClosure A f (& sp) y → y o< & A 446 sc<A : {y : Ordinal} → odef chain y ∨ FClosure A f (& sp) y → y o< & A
427 sc<A {y} (case1 zx) = subst (λ k → k o< (& A)) &iso ( c<→o< (ZChain.chain⊆A zc0 (subst (λ k → odef chain k) (sym &iso) zx ))) 447 sc<A {y} (case1 zx) = subst (λ k → k o< (& A)) &iso ( c<→o< (ZChain.chain⊆A zc0 (subst (λ k → odef chain k) (sym &iso) zx )))
428 sc<A {y} (case2 fx) = subst (λ k → k o< (& A)) &iso ( c<→o< (subst (λ k → odef A k ) (sym &iso) (A∋fc (& sp) f mf fx )) ) 448 sc<A {y} (case2 fx) = subst (λ k → k o< (& A)) &iso ( c<→o< (subst (λ k → odef A k ) (sym &iso) (A∋fc (& sp) f mf fx )) )
429 schain : HOD 449 schain : HOD
486 ... | case1 sp=a | case2 b<sp = <-irr (case2 (subst (λ k → * b < k ) (trans (sym *iso) sp=a) b<sp ) ) (proj1 p ) 506 ... | case1 sp=a | case2 b<sp = <-irr (case2 (subst (λ k → * b < k ) (trans (sym *iso) sp=a) b<sp ) ) (proj1 p )
487 ... | case2 sp<a | case1 b=sp = <-irr (case2 (subst ( λ k → k < * a ) (trans *iso (sym b=sp)) sp<a )) (proj1 p ) 507 ... | case2 sp<a | case1 b=sp = <-irr (case2 (subst ( λ k → k < * a ) (trans *iso (sym b=sp)) sp<a )) (proj1 p )
488 ... | case2 sp<a | case2 b<sp = <-irr (case2 (ptrans b<sp (subst (λ k → k < * a) *iso sp<a ))) (proj1 p ) 508 ... | case2 sp<a | case2 b<sp = <-irr (case2 (ptrans b<sp (subst (λ k → k < * a) *iso sp<a ))) (proj1 p )
489 simm {a} {b} (case2 sa) (case2 sb) p = fcn-imm {A} (& sp) {a} {b} f mf sa sb p 509 simm {a} {b} (case2 sa) (case2 sb) p = fcn-imm {A} (& sp) {a} {b} f mf sa sb p
490 s-ismax : {a b : Ordinal} → odef schain a → b o< osuc x → (ab : odef A b) → 510 s-ismax : {a b : Ordinal} → odef schain a → b o< osuc x → (ab : odef A b) →
491 HasPrev A schain ab f ∨ IsSup A schain scmp s⊆A ab (λ C C⊆A TC → & (SUP.sup (supP C C⊆A TC))) f 511 HasPrev A schain ab f ∨ IsSup A schain ab
492 → * a < * b → odef schain b 512 → * a < * b → odef schain b
493 s-ismax {a} {b} (case1 za) b<x ab (case1 p) a<b with osuc-≡< b<x 513 s-ismax {a} {b} (case1 za) b<ox ab P a<b with osuc-≡< b<ox | ODC.p∨¬p O (HasPrev A schain ab f)-- b is some previous
494 ... | case1 b=x = case2 {!!} -- (subst (λ k → FClosure A f (& sp) k ) (sym (trans b=x x=sup )) (init (SUP.A∋maximal sup0) )) 514 ... | case1 b=x | _ = case2 (subst (λ k → FClosure A f (& sp) k ) (sym (trans b=x x=sup )) (init (SUP.A∋maximal sup0) ))
495 ... | case2 b<x = z21 p where 515 ... | case2 b<x | case1 p = z21 p where
496 z21 : HasPrev A schain ab f → odef schain b 516 z21 : HasPrev A schain ab f → odef schain b
497 z21 record { y = y ; ay = (case1 zy) ; x=fy = x=fy } = 517 z21 record { y = y ; ay = (case1 zy) ; x=fy = x=fy } =
498 case1 (ZChain.is-max zc0 za (zc0-b<x b b<x) ab (case1 record { y = y ; ay = zy ; x=fy = x=fy }) a<b ) 518 case1 (ZChain.is-max zc0 za (zc0-b<x b b<x) ab (case1 record { y = y ; ay = zy ; x=fy = x=fy }) a<b )
499 z21 record { y = y ; ay = (case2 sy) ; x=fy = x=fy } = subst (λ k → odef schain k) (sym x=fy) (case2 (fsuc y sy) ) 519 z21 record { y = y ; ay = (case2 sy) ; x=fy = x=fy } = subst (λ k → odef schain k) (sym x=fy) (case2 (fsuc y sy) )
500 s-ismax {a} {b} (case1 za) b<x ab (case2 p) a<b with osuc-≡< b<x 520 s-ismax {a} {b} (case1 za) b<ox ab (case1 p) a<b | case2 b<x | case2 ¬pr = ⊥-elim ( ¬pr p )
501 ... | case1 b=x = case2 (subst (λ k → FClosure A f (& sp) k ) {!!} (init (SUP.A∋maximal sup0) )) 521 s-ismax {a} {b} (case1 za) b<ox ab (case2 p) a<b | case2 b<x | case2 ¬pr = case1 (ZChain.is-max zc0 za (zc0-b<x b b<x) ab (case2 z22) a<b ) where
502 ... | case2 b<x = {!!} where 522 -- cahin of IsSup A schain ab may larger than chain of zc0 if it has a previous but it is not
503 z22 : IsSup A (ZChain.chain zc0) (ZChain.f-total zc0) (ZChain.chain⊆A zc0) ab supO f → odef schain b 523 z23 : * (IsSup.chain p) ⊆' ZChain.chain zc0
504 z22 p = {!!} 524 z23 = {!!}
505 -- case1 (ZChain.is-max zc0 za (zc0-b<x b lt) ab {!!} a<b ) 525 z22 : IsSup A (ZChain.chain zc0) ab
526 z22 = record { chain = IsSup.chain p ; chain⊆B = z23 ; x<sup = {!!} }
506 s-ismax {a} {b} (case2 sa) b<x ab p a<b = {!!} 527 s-ismax {a} {b} (case2 sa) b<x ab p a<b = {!!}
507 ... | case2 ¬x=sup = -- x is not f y' nor sup of former ZChain from y 528 ... | case2 ¬x=sup = -- x is not f y' nor sup of former ZChain from y
508 record { chain = ZChain.chain zc0 ; chain⊆A = ZChain.chain⊆A zc0 ; f-total = ZChain.f-total zc0 ; f-next = ZChain.f-next zc0 529 record { chain = ZChain.chain zc0 ; chain⊆A = ZChain.chain⊆A zc0 ; f-total = ZChain.f-total zc0 ; f-next = ZChain.f-next zc0
509 ; initial = ZChain.initial zc0 ; f-immediate = ZChain.f-immediate zc0 ; chain∋x = ZChain.chain∋x zc0 ; is-max = z18 } where -- no extention 530 ; initial = ZChain.initial zc0 ; f-immediate = ZChain.f-immediate zc0 ; chain∋x = ZChain.chain∋x zc0 ; is-max = z18 } where -- no extention
510 z18 : {a b : Ordinal} → odef (ZChain.chain zc0) a → b o< osuc x → (ab : odef A b) → 531 z18 : {a b : Ordinal} → odef (ZChain.chain zc0) a → b o< osuc x → (ab : odef A b) →
511 HasPrev A (ZChain.chain zc0) ab f ∨ IsSup A (ZChain.chain zc0) (ZChain.f-total zc0) (ZChain.chain⊆A zc0) ab supO f → 532 HasPrev A (ZChain.chain zc0) ab f ∨ IsSup A (ZChain.chain zc0) ab →
512 * a < * b → odef (ZChain.chain zc0) b 533 * a < * b → odef (ZChain.chain zc0) b
513 z18 {a} {b} za b<x ab p a<b with osuc-≡< b<x 534 z18 {a} {b} za b<x ab p a<b with osuc-≡< b<x
514 ... | case2 lt = ZChain.is-max zc0 za (zc0-b<x b lt) ab p a<b 535 ... | case2 lt = ZChain.is-max zc0 za (zc0-b<x b lt) ab p a<b
515 ... | case1 b=x with p 536 ... | case1 b=x with p
516 ... | case1 pr = ⊥-elim ( ¬fy<x record {y = HasPrev.y pr ; ay = HasPrev.ay pr ; x=fy = trans (trans &iso (sym b=x) ) (HasPrev.x=fy pr ) } ) 537 ... | case1 pr = ⊥-elim ( ¬fy<x record {y = HasPrev.y pr ; ay = HasPrev.ay pr ; x=fy = trans (trans &iso (sym b=x) ) (HasPrev.x=fy pr ) } )
517 ... | case2 b=sup = ⊥-elim ( ¬x=sup {!!} ) 538 ... | case2 b=sup = ⊥-elim ( ¬x=sup record { chain = IsSup.chain b=sup ; chain⊆B = IsSup.chain⊆B b=sup
539 ; x<sup = λ {y} zy → subst (λ k → (y ≡ k) ∨ (y << k)) (trans b=x (sym &iso)) (IsSup.x<sup b=sup zy) } )
518 ... | no ¬ox = {!!} where --- limit ordinal case 540 ... | no ¬ox = {!!} where --- limit ordinal case
519 record UZFChain (z : Ordinal) : Set n where -- Union of ZFChain from y which has maximality o< x 541 record UZFChain (z : Ordinal) : Set n where -- Union of ZFChain from y which has maximality o< x
520 field 542 field
521 u : Ordinal 543 u : Ordinal
522 u<x : u o< x 544 u<x : u o< x