# HG changeset patch # User huffman # Date 1244009165 25200 # Node ID 0baaad47cef21aca392d94e6e48269fff69aa2db # Parent e37967787a4feaf76c88b3c32a28aef4f808b282 class complete_space diff -r e37967787a4f -r 0baaad47cef2 src/HOL/SEQ.thy --- a/src/HOL/SEQ.thy Tue Jun 02 22:35:56 2009 -0700 +++ b/src/HOL/SEQ.thy Tue Jun 02 23:06:05 2009 -0700 @@ -1034,9 +1034,11 @@ subsubsection {* Cauchy Sequences are Convergent *} -axclass banach \ real_normed_vector +axclass complete_space \ metric_space Cauchy_convergent: "Cauchy X \ convergent X" +axclass banach \ real_normed_vector, complete_space + theorem LIMSEQ_imp_Cauchy: assumes X: "X ----> a" shows "Cauchy X" proof (rule metric_CauchyI) @@ -1061,6 +1063,16 @@ unfolding convergent_def by (erule exE, erule LIMSEQ_imp_Cauchy) +lemma Cauchy_convergent_iff: + fixes X :: "nat \ 'a::complete_space" + shows "Cauchy X = convergent X" +by (fast intro: Cauchy_convergent convergent_Cauchy) + +lemma convergent_subseq_convergent: + fixes X :: "nat \ 'a::complete_space" + shows "\ convergent X; subseq f \ \ convergent (X o f)" + by (simp add: Cauchy_subseq_Cauchy Cauchy_convergent_iff [symmetric]) + text {* Proof that Cauchy sequences converge based on the one from http://pirate.shu.edu/~wachsmut/ira/numseq/proofs/cauconv.html @@ -1174,16 +1186,6 @@ instance real :: banach by intro_classes (rule real_Cauchy_convergent) -lemma Cauchy_convergent_iff: - fixes X :: "nat \ 'a::banach" - shows "Cauchy X = convergent X" -by (fast intro: Cauchy_convergent convergent_Cauchy) - -lemma convergent_subseq_convergent: - fixes X :: "nat \ 'a::banach" - shows "\ convergent X; subseq f \ \ convergent (X o f)" - by (simp add: Cauchy_subseq_Cauchy Cauchy_convergent_iff [symmetric]) - subsection {* Power Sequences *}