1.1 --- a/src/HOL/Lim.thy Wed Aug 17 09:59:10 2011 -0700
1.2 +++ b/src/HOL/Lim.thy Wed Aug 17 11:06:39 2011 -0700
1.3 @@ -132,12 +132,8 @@
1.4 assumes f: "f -- a --> l"
1.5 assumes le: "\<And>x. x \<noteq> a \<Longrightarrow> dist (g x) m \<le> dist (f x) l"
1.6 shows "g -- a --> m"
1.7 -apply (rule tendstoI, drule tendstoD [OF f])
1.8 -apply (simp add: eventually_at_topological, safe)
1.9 -apply (rule_tac x="S" in exI, safe)
1.10 -apply (drule_tac x="x" in bspec, safe)
1.11 -apply (erule (1) order_le_less_trans [OF le])
1.12 -done
1.13 + by (rule metric_tendsto_imp_tendsto [OF f],
1.14 + auto simp add: eventually_at_topological le)
1.15
1.16 lemma LIM_imp_LIM:
1.17 fixes f :: "'a::topological_space \<Rightarrow> 'b::real_normed_vector"
1.18 @@ -145,9 +141,8 @@
1.19 assumes f: "f -- a --> l"
1.20 assumes le: "\<And>x. x \<noteq> a \<Longrightarrow> norm (g x - m) \<le> norm (f x - l)"
1.21 shows "g -- a --> m"
1.22 -apply (rule metric_LIM_imp_LIM [OF f])
1.23 -apply (simp add: dist_norm le)
1.24 -done
1.25 + by (rule metric_LIM_imp_LIM [OF f],
1.26 + simp add: dist_norm le)
1.27
1.28 lemma LIM_norm:
1.29 fixes f :: "'a::topological_space \<Rightarrow> 'b::real_normed_vector"
2.1 --- a/src/HOL/Limits.thy Wed Aug 17 09:59:10 2011 -0700
2.2 +++ b/src/HOL/Limits.thy Wed Aug 17 11:06:39 2011 -0700
2.3 @@ -627,6 +627,17 @@
2.4 by (rule eventually_mono)
2.5 qed
2.6
2.7 +lemma metric_tendsto_imp_tendsto:
2.8 + assumes f: "(f ---> a) F"
2.9 + assumes le: "eventually (\<lambda>x. dist (g x) b \<le> dist (f x) a) F"
2.10 + shows "(g ---> b) F"
2.11 +proof (rule tendstoI)
2.12 + fix e :: real assume "0 < e"
2.13 + with f have "eventually (\<lambda>x. dist (f x) a < e) F" by (rule tendstoD)
2.14 + with le show "eventually (\<lambda>x. dist (g x) b < e) F"
2.15 + using le_less_trans by (rule eventually_elim2)
2.16 +qed
2.17 +
2.18 subsubsection {* Distance and norms *}
2.19
2.20 lemma tendsto_dist [tendsto_intros]: