changeset 57598 | 56ed992b6d65 |
parent 57447 | 87429bdecad5 |
child 58195 | 1fee63e0377d |
--- a/src/HOL/Finite_Set.thy Sun Jul 20 22:05:35 2014 +0200 +++ b/src/HOL/Finite_Set.thy Mon Jul 21 17:51:11 2014 +0200 @@ -733,6 +733,11 @@ then show ?thesis by simp qed +lemma fold_set_union_disj: + assumes "finite A" "finite B" "A \<inter> B = {}" + shows "Finite_Set.fold f z (A \<union> B) = Finite_Set.fold f (Finite_Set.fold f z A) B" +using assms(2,1,3) by induction simp_all + end text{* Other properties of @{const fold}: *}