changeset 14050 | 826037db30cd |
parent 14025 | d9b155757dc8 |
child 14099 | 55d244f3c86d |
--- a/src/HOL/List.thy Tue May 27 17:39:43 2003 +0200 +++ b/src/HOL/List.thy Wed May 28 10:47:54 2003 +0200 @@ -885,6 +885,12 @@ apply auto done +lemma take_add [rule_format]: + "\<forall>i. i+j \<le> length(xs) --> take (i+j) xs = take i xs @ take j (drop i xs)" +apply (induct xs, auto) +apply (case_tac i, simp_all) +done + subsection {* @{text takeWhile} and @{text dropWhile} *}