author | nipkow |
Sun, 04 Nov 2012 18:41:27 +0100 | |
changeset 50008 | eb7f574d0303 |
parent 50007 | 56f269baae76 |
child 50009 | e48de0410307 |
--- a/src/HOL/Library/While_Combinator.thy Sun Nov 04 18:38:18 2012 +0100 +++ b/src/HOL/Library/While_Combinator.thy Sun Nov 04 18:41:27 2012 +0100 @@ -83,7 +83,7 @@ definition while :: "('a \<Rightarrow> bool) \<Rightarrow> ('a \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'a" where "while b c s = the (while_option b c s)" -lemma while_unfold: +lemma while_unfold [code]: "while b c s = (if b s then while b c (c s) else s)" unfolding while_def by (subst while_option_unfold) simp