1.1 --- a/src/HOL/Multivariate_Analysis/Topology_Euclidean_Space.thy Thu Jan 17 15:50:56 2013 +0100
1.2 +++ b/src/HOL/Multivariate_Analysis/Topology_Euclidean_Space.thy Tue Jan 15 19:28:48 2013 -0800
1.3 @@ -2152,7 +2152,9 @@
1.4 unfolding bounded_def dist_real_def apply(rule_tac x=0 in exI)
1.5 using assms by auto
1.6
1.7 -lemma bounded_empty[simp]: "bounded {}" by (simp add: bounded_def)
1.8 +lemma bounded_empty [simp]: "bounded {}"
1.9 + by (simp add: bounded_def)
1.10 +
1.11 lemma bounded_subset: "bounded T \<Longrightarrow> S \<subseteq> T ==> bounded S"
1.12 by (metis bounded_def subset_eq)
1.13
1.14 @@ -2188,17 +2190,6 @@
1.15 lemma bounded_ball[simp,intro]: "bounded(ball x e)"
1.16 by (metis ball_subset_cball bounded_cball bounded_subset)
1.17
1.18 -lemma finite_imp_bounded[intro]:
1.19 - fixes S :: "'a::metric_space set" assumes "finite S" shows "bounded S"
1.20 -proof-
1.21 - { fix a and F :: "'a set" assume as:"bounded F"
1.22 - then obtain x e where "\<forall>y\<in>F. dist x y \<le> e" unfolding bounded_def by auto
1.23 - hence "\<forall>y\<in>(insert a F). dist x y \<le> max e (dist x a)" by auto
1.24 - hence "bounded (insert a F)" unfolding bounded_def by (intro exI)
1.25 - }
1.26 - thus ?thesis using finite_induct[of S bounded] using bounded_empty assms by auto
1.27 -qed
1.28 -
1.29 lemma bounded_Un[simp]: "bounded (S \<union> T) \<longleftrightarrow> bounded S \<and> bounded T"
1.30 apply (auto simp add: bounded_def)
1.31 apply (rename_tac x y r s)
1.32 @@ -2214,6 +2205,16 @@
1.33 lemma bounded_Union[intro]: "finite F \<Longrightarrow> (\<forall>S\<in>F. bounded S) \<Longrightarrow> bounded(\<Union>F)"
1.34 by (induct rule: finite_induct[of F], auto)
1.35
1.36 +lemma bounded_insert [simp]: "bounded (insert x S) \<longleftrightarrow> bounded S"
1.37 +proof -
1.38 + have "\<forall>y\<in>{x}. dist x y \<le> 0" by simp
1.39 + hence "bounded {x}" unfolding bounded_def by fast
1.40 + thus ?thesis by (metis insert_is_Un bounded_Un)
1.41 +qed
1.42 +
1.43 +lemma finite_imp_bounded [intro]: "finite S \<Longrightarrow> bounded S"
1.44 + by (induct set: finite, simp_all)
1.45 +
1.46 lemma bounded_pos: "bounded S \<longleftrightarrow> (\<exists>b>0. \<forall>x\<in> S. norm x <= b)"
1.47 apply (simp add: bounded_iff)
1.48 apply (subgoal_tac "\<And>x (y::real). 0 < 1 + abs y \<and> (x <= y \<longrightarrow> x <= 1 + abs y)")
1.49 @@ -2226,9 +2227,6 @@
1.50 apply (metis Diff_subset bounded_subset)
1.51 done
1.52
1.53 -lemma bounded_insert[intro]:"bounded(insert x S) \<longleftrightarrow> bounded S"
1.54 - by (metis Diff_cancel Un_empty_right Un_insert_right bounded_Un bounded_subset finite.emptyI finite_imp_bounded infinite_remove subset_insertI)
1.55 -
1.56 lemma not_bounded_UNIV[simp, intro]:
1.57 "\<not> bounded (UNIV :: 'a::{real_normed_vector, perfect_space} set)"
1.58 proof(auto simp add: bounded_pos not_le)
1.59 @@ -5063,14 +5061,14 @@
1.60 qed
1.61
1.62 lemma continuous_attains_sup:
1.63 - fixes f :: "'a::metric_space \<Rightarrow> real"
1.64 + fixes f :: "'a::topological_space \<Rightarrow> real"
1.65 shows "compact s \<Longrightarrow> s \<noteq> {} \<Longrightarrow> continuous_on s f
1.66 ==> (\<exists>x \<in> s. \<forall>y \<in> s. f y \<le> f x)"
1.67 using compact_attains_sup[of "f ` s"]
1.68 using compact_continuous_image[of s f] by auto
1.69
1.70 lemma continuous_attains_inf:
1.71 - fixes f :: "'a::metric_space \<Rightarrow> real"
1.72 + fixes f :: "'a::topological_space \<Rightarrow> real"
1.73 shows "compact s \<Longrightarrow> s \<noteq> {} \<Longrightarrow> continuous_on s f
1.74 \<Longrightarrow> (\<exists>x \<in> s. \<forall>y \<in> s. f x \<le> f y)"
1.75 using compact_attains_inf[of "f ` s"]