comparison OD.agda @ 328:72f3e3b44c27

intoduce ωmax
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Sun, 05 Jul 2020 11:40:55 +0900
parents cde56f704eac
children 0faa7120e4b5
comparison
equal deleted inserted replaced
327:cde56f704eac 328:72f3e3b44c27
317 data infinite-d : ( x : Ordinal ) → Set n where 317 data infinite-d : ( x : Ordinal ) → Set n where
318 iφ : infinite-d o∅ 318 iφ : infinite-d o∅
319 isuc : {x : Ordinal } → infinite-d x → 319 isuc : {x : Ordinal } → infinite-d x →
320 infinite-d (od→ord ( Union (ord→od x , (ord→od x , ord→od x ) ) )) 320 infinite-d (od→ord ( Union (ord→od x , (ord→od x , ord→od x ) ) ))
321 321
322 -- ω can be diverged in our case, since we have no restriction on the corresponding ordinal of a pair.
323 -- We simply assumes nfinite-d y has a maximum.
324 --
325 -- This means that many of OD cannot be HODs because of the od→ord mapping divergence.
326 -- We should have some axioms to prevent this, but it may complicate thins.
327 --
328 postulate
329 ωmax : Ordinal
330 <ωmax : {y : Ordinal} → infinite-d y → y o< ωmax
331
322 infinite : HOD 332 infinite : HOD
323 infinite = record { od = record { def = λ x → infinite-d x } ; odmax = next o∅ ; <odmax = lemma } where 333 infinite = record { od = record { def = λ x → infinite-d x } ; odmax = ωmax ; <odmax = <ωmax }
324 u : HOD → HOD
325 u x = Union (x , (x , x))
326 lemma1 : {x : HOD} → u x ⊆ Union (u x , (u x , u x))
327 lemma1 {x} = record { incl = λ {y} lt → lemma2 y lt } where
328 lemma2 : (y : HOD) → u x ∋ y → ((z : Ordinal) → (z ≡ od→ord (u x)) ∨ (z ≡ od→ord (u x , u x)) ∧ def (od (ord→od z)) (od→ord y) → ⊥) → ⊥
329 lemma2 y lt not = not (od→ord (u x)) record { proj1 = case1 refl ; proj2 = subst (λ k → def (od k) (od→ord y) ) (sym oiso) lt }
330 lemma3 : {x : HOD} → od→ord (u x) o< osuc (od→ord ( Union (u x , (u x , u x)) ))
331 lemma3 {x} = od⊆→o≤ lemma1
332 lemma6 : {x y : HOD} → y ≡ u x → HOD
333 lemma6 {x} _ = x
334 lemma : {y : Ordinal} → infinite-d y → y o< next o∅
335 lemma {y} = TransFinite {λ x → infinite-d x → x o< next o∅ } ind y where
336 ind : (x : Ordinal) → ((z : Ordinal) → z o< x → infinite-d z → z o< (next o∅)) →
337 infinite-d x → x o< (next o∅)
338 ind o∅ prev iφ = proj1 next-limit
339 ind x prev (isuc lt) = lemma0 {_} {x} {!!} where
340 lemma0 : {x z : Ordinal} → x o< od→ord (Union (ord→od z , (ord→od z , ord→od z))) → od→ord (Union (ord→od x , (ord→od x , ord→od x))) o< next o∅
341 lemma0 {x} with prev x {!!}
342 ... | t = {!!}
343 334
344 _=h=_ : (x y : HOD) → Set n 335 _=h=_ : (x y : HOD) → Set n
345 x =h= y = od x == od y 336 x =h= y = od x == od y
346 337
347 infixr 200 _∈_ 338 infixr 200 _∈_