Mercurial > hg > Members > atton > similar_monad

changeset 31:33b386de3f56

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Proof list-associative
author Yasutaka Higa <e115763@ie.u-ryukyu.ac.jp>
date Sat, 18 Oct 2014 13:38:29 +0900
parents c2f40b6d4027
children 71906644d206
files agda/list.agda
diffstat 1 files changed, 6 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/agda/list.agda	Tue Oct 07 15:32:11 2014 +0900
+++ b/agda/list.agda	Sat Oct 18 13:38:29 2014 +0900
@@ -24,4 +24,9 @@
     x :: (xs ++ [])
   ≡⟨ cong (_::_ x) (empty-append xs) ⟩
     x :: xs
-  ∎
\ No newline at end of file
+  ∎
+
+
+list-associative : {A : Set} -> (a b c : List A) -> (a ++ (b ++ c)) ≡ ((a ++ b) ++ c)
+list-associative [] b c = refl
+list-associative (x :: a) b c = cong (_::_ x) (list-associative a b c)
\ No newline at end of file