diff Ordinals.agda @ 341:27d2933c4bd7

...
author Shinji KONO <kono@ie.u-ryukyu.ac.jp>
date Mon, 13 Jul 2020 13:29:38 +0900
parents 639fbb6284d8
children b1ccdbb14c92
line wrap: on
line diff
--- a/Ordinals.agda	Mon Jul 13 09:26:34 2020 +0900
+++ b/Ordinals.agda	Mon Jul 13 13:29:38 2020 +0900
@@ -231,6 +231,13 @@
         nexto=n : {x y : Ordinal} → x o< next (osuc y)  → x o< next y 
         nexto=n {x} {y} x<noy = next< (proj1 (proj2 next-limit) _ (proj1 next-limit)) x<noy
 
+        nexto≡ : {x : Ordinal} → next x ≡ next (osuc x)  
+        nexto≡ {x} with trio< (next x) (next (osuc x) ) 
+        nexto≡ {x} | tri< a ¬b ¬c = {!!}
+        nexto≡ {x} | tri≈ ¬a b ¬c = b
+        nexto≡ {x} | tri> ¬a ¬b c = ⊥-elim ((proj2 (proj2 next-limit)) _ (ordtrans <-osuc (proj1 next-limit)) c
+           (λ z eq → o<¬≡ (sym eq) (proj1 (proj2 next-limit) _ (ordtrans <-osuc (subst (λ k → k o< next (osuc x)) eq {!!} )))))
+
         record OrdinalSubset (maxordinal : Ordinal) : Set (suc n) where
           field
             os→ : (x : Ordinal) → x o< maxordinal → Ordinal