# HG changeset patch # User hoelzl # Date 1365512855 -7200 # Node ID 8c38147d404e903f47c51840b76767be4fcb2620 # Parent b6675f4549d8ce33d8b2e5bb5eeb685a3a631542 add continuous_on rules for products diff -r b6675f4549d8 -r 8c38147d404e src/HOL/Library/Product_Vector.thy --- a/src/HOL/Library/Product_Vector.thy Tue Apr 09 14:13:13 2013 +0200 +++ b/src/HOL/Library/Product_Vector.thy Tue Apr 09 15:07:35 2013 +0200 @@ -202,6 +202,15 @@ lemma continuous_Pair[continuous_intros]: "continuous F f \ continuous F g \ continuous F (\x. (f x, g x))" unfolding continuous_def by (rule tendsto_Pair) +lemma continuous_on_fst[continuous_on_intros]: "continuous_on s f \ continuous_on s (\x. fst (f x))" + unfolding continuous_on_def by (auto intro: tendsto_fst) + +lemma continuous_on_snd[continuous_on_intros]: "continuous_on s f \ continuous_on s (\x. snd (f x))" + unfolding continuous_on_def by (auto intro: tendsto_snd) + +lemma continuous_on_Pair[continuous_on_intros]: "continuous_on s f \ continuous_on s g \ continuous_on s (\x. (f x, g x))" + unfolding continuous_on_def by (auto intro: tendsto_Pair) + lemma isCont_fst [simp]: "isCont f a \ isCont (\x. fst (f x)) a" by (fact continuous_fst)