--- a/src/HOL/Analysis/Abstract_Limits.thy Thu Mar 07 14:08:05 2019 +0000
+++ b/src/HOL/Analysis/Abstract_Limits.thy Thu Mar 07 16:59:12 2019 +0000
@@ -44,32 +44,32 @@
subsection\<open>Limits in a topological space\<close>
-definition limit :: "'a topology \<Rightarrow> ('b \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'b filter \<Rightarrow> bool" where
- "limit X f l F \<equiv> l \<in> topspace X \<and> (\<forall>U. openin X U \<and> l \<in> U \<longrightarrow> eventually (\<lambda>x. f x \<in> U) F)"
+definition limitin :: "'a topology \<Rightarrow> ('b \<Rightarrow> 'a) \<Rightarrow> 'a \<Rightarrow> 'b filter \<Rightarrow> bool" where
+ "limitin X f l F \<equiv> l \<in> topspace X \<and> (\<forall>U. openin X U \<and> l \<in> U \<longrightarrow> eventually (\<lambda>x. f x \<in> U) F)"
-lemma limit_euclideanreal_iff [simp]: "limit euclideanreal f l F \<longleftrightarrow> (f \<longlongrightarrow> l) F"
- by (auto simp: limit_def tendsto_def)
+lemma limitin_euclideanreal_iff [simp]: "limitin euclideanreal f l F \<longleftrightarrow> (f \<longlongrightarrow> l) F"
+ by (auto simp: limitin_def tendsto_def)
-lemma limit_in_topspace: "limit X f l F \<Longrightarrow> l \<in> topspace X"
- by (simp add: limit_def)
+lemma limitin_topspace: "limitin X f l F \<Longrightarrow> l \<in> topspace X"
+ by (simp add: limitin_def)
-lemma limit_const: "limit X (\<lambda>a. l) l F \<longleftrightarrow> l \<in> topspace X"
- by (simp add: limit_def)
+lemma limitin_const: "limitin X (\<lambda>a. l) l F \<longleftrightarrow> l \<in> topspace X"
+ by (simp add: limitin_def)
-lemma limit_real_const: "limit euclideanreal (\<lambda>a. l) l F"
- by (simp add: limit_def)
+lemma limitin_real_const: "limitin euclideanreal (\<lambda>a. l) l F"
+ by (simp add: limitin_def)
-lemma limit_eventually:
- "\<lbrakk>l \<in> topspace X; eventually (\<lambda>x. f x = l) F\<rbrakk> \<Longrightarrow> limit X f l F"
- by (auto simp: limit_def eventually_mono)
+lemma limitin_eventually:
+ "\<lbrakk>l \<in> topspace X; eventually (\<lambda>x. f x = l) F\<rbrakk> \<Longrightarrow> limitin X f l F"
+ by (auto simp: limitin_def eventually_mono)
-lemma limit_subsequence:
- "\<lbrakk>strict_mono r; limit X f l sequentially\<rbrakk> \<Longrightarrow> limit X (f \<circ> r) l sequentially"
- unfolding limit_def using eventually_subseq by fastforce
+lemma limitin_subsequence:
+ "\<lbrakk>strict_mono r; limitin X f l sequentially\<rbrakk> \<Longrightarrow> limitin X (f \<circ> r) l sequentially"
+ unfolding limitin_def using eventually_subseq by fastforce
-lemma limit_subtopology:
- "limit (subtopology X S) f l F
- \<longleftrightarrow> l \<in> S \<and> eventually (\<lambda>a. f a \<in> S) F \<and> limit X f l F" (is "?lhs = ?rhs")
+lemma limitin_subtopology:
+ "limitin (subtopology X S) f l F
+ \<longleftrightarrow> l \<in> S \<and> eventually (\<lambda>a. f a \<in> S) F \<and> limitin X f l F" (is "?lhs = ?rhs")
proof (cases "l \<in> S \<inter> topspace X")
case True
show ?thesis
@@ -77,84 +77,84 @@
assume L: ?lhs
with True
have "\<forall>\<^sub>F b in F. f b \<in> topspace X \<inter> S"
- by (metis (no_types) limit_def openin_topspace topspace_subtopology)
+ by (metis (no_types) limitin_def openin_topspace topspace_subtopology)
with L show ?rhs
- apply (clarsimp simp add: limit_def eventually_mono topspace_subtopology openin_subtopology_alt)
+ apply (clarsimp simp add: limitin_def eventually_mono topspace_subtopology openin_subtopology_alt)
apply (drule_tac x="S \<inter> U" in spec, force simp: elim: eventually_mono)
done
next
assume ?rhs
then show ?lhs
using eventually_elim2
- by (fastforce simp add: limit_def topspace_subtopology openin_subtopology_alt)
+ by (fastforce simp add: limitin_def topspace_subtopology openin_subtopology_alt)
qed
-qed (auto simp: limit_def topspace_subtopology)
+qed (auto simp: limitin_def topspace_subtopology)
-lemma limit_sequentially:
- "limit X S l sequentially \<longleftrightarrow>
+lemma limitin_sequentially:
+ "limitin X S l sequentially \<longleftrightarrow>
l \<in> topspace X \<and> (\<forall>U. openin X U \<and> l \<in> U \<longrightarrow> (\<exists>N. \<forall>n. N \<le> n \<longrightarrow> S n \<in> U))"
- by (simp add: limit_def eventually_sequentially)
+ by (simp add: limitin_def eventually_sequentially)
-lemma limit_sequentially_offset:
- "limit X f l sequentially \<Longrightarrow> limit X (\<lambda>i. f (i + k)) l sequentially"
- unfolding limit_sequentially
+lemma limitin_sequentially_offset:
+ "limitin X f l sequentially \<Longrightarrow> limitin X (\<lambda>i. f (i + k)) l sequentially"
+ unfolding limitin_sequentially
by (metis add.commute le_add2 order_trans)
-lemma limit_sequentially_offset_rev:
- assumes "limit X (\<lambda>i. f (i + k)) l sequentially"
- shows "limit X f l sequentially"
+lemma limitin_sequentially_offset_rev:
+ assumes "limitin X (\<lambda>i. f (i + k)) l sequentially"
+ shows "limitin X f l sequentially"
proof -
have "\<exists>N. \<forall>n\<ge>N. f n \<in> U" if U: "openin X U" "l \<in> U" for U
proof -
obtain N where "\<And>n. n\<ge>N \<Longrightarrow> f (n + k) \<in> U"
- using assms U unfolding limit_sequentially by blast
+ using assms U unfolding limitin_sequentially by blast
then have "\<forall>n\<ge>N+k. f n \<in> U"
by (metis add_leD2 le_add_diff_inverse ordered_cancel_comm_monoid_diff_class.le_diff_conv2 add.commute)
then show ?thesis ..
qed
with assms show ?thesis
- unfolding limit_sequentially
+ unfolding limitin_sequentially
by simp
qed
-lemma limit_atin:
- "limit Y f y (atin X x) \<longleftrightarrow>
+lemma limitin_atin:
+ "limitin Y f y (atin X x) \<longleftrightarrow>
y \<in> topspace Y \<and>
(x \<in> topspace X
\<longrightarrow> (\<forall>V. openin Y V \<and> y \<in> V
\<longrightarrow> (\<exists>U. openin X U \<and> x \<in> U \<and> f ` (U - {x}) \<subseteq> V)))"
- by (auto simp: limit_def eventually_atin image_subset_iff)
+ by (auto simp: limitin_def eventually_atin image_subset_iff)
-lemma limit_atin_self:
- "limit Y f (f a) (atin X a) \<longleftrightarrow>
+lemma limitin_atin_self:
+ "limitin Y f (f a) (atin X a) \<longleftrightarrow>
f a \<in> topspace Y \<and>
(a \<in> topspace X
\<longrightarrow> (\<forall>V. openin Y V \<and> f a \<in> V
\<longrightarrow> (\<exists>U. openin X U \<and> a \<in> U \<and> f ` U \<subseteq> V)))"
- unfolding limit_atin by fastforce
+ unfolding limitin_atin by fastforce
-lemma limit_trivial:
- "\<lbrakk>trivial_limit F; y \<in> topspace X\<rbrakk> \<Longrightarrow> limit X f y F"
- by (simp add: limit_def)
+lemma limitin_trivial:
+ "\<lbrakk>trivial_limit F; y \<in> topspace X\<rbrakk> \<Longrightarrow> limitin X f y F"
+ by (simp add: limitin_def)
-lemma limit_transform_eventually:
- "\<lbrakk>eventually (\<lambda>x. f x = g x) F; limit X f l F\<rbrakk> \<Longrightarrow> limit X g l F"
- unfolding limit_def using eventually_elim2 by fastforce
+lemma limitin_transform_eventually:
+ "\<lbrakk>eventually (\<lambda>x. f x = g x) F; limitin X f l F\<rbrakk> \<Longrightarrow> limitin X g l F"
+ unfolding limitin_def using eventually_elim2 by fastforce
lemma continuous_map_limit:
- assumes "continuous_map X Y g" and f: "limit X f l F"
- shows "limit Y (g \<circ> f) (g l) F"
+ assumes "continuous_map X Y g" and f: "limitin X f l F"
+ shows "limitin Y (g \<circ> f) (g l) F"
proof -
have "g l \<in> topspace Y"
- by (meson assms continuous_map_def limit_in_topspace)
+ by (meson assms continuous_map_def limitin_topspace)
moreover
have "\<And>U. \<lbrakk>\<forall>V. openin X V \<and> l \<in> V \<longrightarrow> (\<forall>\<^sub>F x in F. f x \<in> V); openin Y U; g l \<in> U\<rbrakk>
\<Longrightarrow> \<forall>\<^sub>F x in F. g (f x) \<in> U"
using assms eventually_mono
- by (fastforce simp: limit_def dest!: openin_continuous_map_preimage)
+ by (fastforce simp: limitin_def dest!: openin_continuous_map_preimage)
ultimately show ?thesis
- using f by (fastforce simp add: limit_def)
+ using f by (fastforce simp add: limitin_def)
qed
@@ -171,9 +171,9 @@
"topcontinuous_at X Y f x \<longleftrightarrow>
x \<in> topspace X \<and>
(\<forall>x \<in> topspace X. f x \<in> topspace Y) \<and>
- limit Y f (f x) (atin X x)"
+ limitin Y f (f x) (atin X x)"
unfolding topcontinuous_at_def
- by (fastforce simp add: limit_atin)+
+ by (fastforce simp add: limitin_atin)+
lemma continuous_map_eq_topcontinuous_at:
"continuous_map X Y f \<longleftrightarrow> (\<forall>x \<in> topspace X. topcontinuous_at X Y f x)"
@@ -193,11 +193,11 @@
qed
lemma continuous_map_atin:
- "continuous_map X Y f \<longleftrightarrow> (\<forall>x \<in> topspace X. limit Y f (f x) (atin X x))"
- by (auto simp: limit_def topcontinuous_at_atin continuous_map_eq_topcontinuous_at)
+ "continuous_map X Y f \<longleftrightarrow> (\<forall>x \<in> topspace X. limitin Y f (f x) (atin X x))"
+ by (auto simp: limitin_def topcontinuous_at_atin continuous_map_eq_topcontinuous_at)
-lemma limit_continuous_map:
- "\<lbrakk>continuous_map X Y f; a \<in> topspace X; f a = b\<rbrakk> \<Longrightarrow> limit Y f b (atin X a)"
+lemma limitin_continuous_map:
+ "\<lbrakk>continuous_map X Y f; a \<in> topspace X; f a = b\<rbrakk> \<Longrightarrow> limitin Y f b (atin X a)"
by (auto simp: continuous_map_atin)