diff -r 3ca9e79ac926 -r a14d2a854c02 src/HOL/List.thy --- a/src/HOL/List.thy Tue Sep 03 00:51:08 2013 +0200 +++ b/src/HOL/List.thy Tue Sep 03 01:12:40 2013 +0200 @@ -722,12 +722,18 @@ using `xs \ []` proof (induct xs) case Nil then show ?case by simp next - case (Cons x xs) show ?case proof (cases xs) - case Nil with single show ?thesis by simp + case (Cons x xs) + show ?case + proof (cases xs) + case Nil + with single show ?thesis by simp next - case Cons then have "xs \ []" by simp - moreover with Cons.hyps have "P xs" . - ultimately show ?thesis by (rule cons) + case Cons + show ?thesis + proof (rule cons) + from Cons show "xs \ []" by simp + with Cons.hyps show "P xs" . + qed qed qed @@ -1061,12 +1067,13 @@ lemma map_eq_imp_length_eq: assumes "map f xs = map g ys" shows "length xs = length ys" -using assms proof (induct ys arbitrary: xs) + using assms +proof (induct ys arbitrary: xs) case Nil then show ?case by simp next case (Cons y ys) then obtain z zs where xs: "xs = z # zs" by auto from Cons xs have "map f zs = map g ys" by simp - moreover with Cons have "length zs = length ys" by blast + with Cons have "length zs = length ys" by blast with xs show ?case by simp qed @@ -1669,10 +1676,10 @@ hence n: "n < Suc (length xs)" by simp moreover { assume "n < length xs" - with n obtain n' where "length xs - n = Suc n'" + with n obtain n' where n': "length xs - n = Suc n'" by (cases "length xs - n", auto) moreover - then have "length xs - Suc n = n'" by simp + from n' have "length xs - Suc n = n'" by simp ultimately have "xs ! (length xs - Suc n) = (x # xs) ! (length xs - n)" by simp } @@ -3801,14 +3808,12 @@ then have "\m n zs. concat (replicate m zs) = xs' \ concat (replicate n zs) = ws" using False and `xs' \ []` and `ys' = xs' @ ws` and len by (intro less.hyps) auto - then obtain m n zs where "concat (replicate m zs) = xs'" + then obtain m n zs where *: "concat (replicate m zs) = xs'" and "concat (replicate n zs) = ws" by blast - moreover then have "concat (replicate (m + n) zs) = ys'" using `ys' = xs' @ ws` by (simp add: replicate_add) - ultimately - show ?thesis by blast + with * show ?thesis by blast qed then show ?case using xs'_def ys'_def by metis @@ -4074,8 +4079,8 @@ case Nil thus ?case by simp next case (Cons a xs) - moreover hence "!x. x: set xs \ x \ a" by auto - ultimately show ?case by(simp add: sublist_Cons cong:filter_cong) + then have "!x. x: set xs \ x \ a" by auto + with Cons show ?case by(simp add: sublist_Cons cong:filter_cong) qed @@ -4195,8 +4200,8 @@ hence "foldr (\xs. max (length xs)) xss 0 = 0" proof (induct xss) case (Cons x xs) - moreover hence "x = []" by (cases x) auto - ultimately show ?case by auto + then have "x = []" by (cases x) auto + with Cons show ?case by auto qed simp thus ?thesis using True by simp next @@ -4585,7 +4590,7 @@ proof - from assms have "map f xs = map f ys" by (simp add: sorted_distinct_set_unique) - moreover with `inj_on f (set xs \ set ys)` show "xs = ys" + with `inj_on f (set xs \ set ys)` show "xs = ys" by (blast intro: map_inj_on) qed @@ -4620,11 +4625,12 @@ lemma foldr_max_sorted: assumes "sorted (rev xs)" shows "foldr max xs y = (if xs = [] then y else max (xs ! 0) y)" -using assms proof (induct xs) + using assms +proof (induct xs) case (Cons x xs) - moreover hence "sorted (rev xs)" using sorted_append by auto - ultimately show ?case - by (cases xs, auto simp add: sorted_append max_def) + then have "sorted (rev xs)" using sorted_append by auto + with Cons show ?case + by (cases xs) (auto simp add: sorted_append max_def) qed simp lemma filter_equals_takeWhile_sorted_rev: