new theorem about zero limits
authorpaulson <lp15@cam.ac.uk>
Wed, 02 Apr 2014 16:45:31 +0100
changeset 56366 0362c3bb4d02
parent 56365 713f9b9a7e51
child 56368 0646f63a02b7
new theorem about zero limits
src/HOL/Limits.thy
--- a/src/HOL/Limits.thy	Wed Apr 02 16:34:37 2014 +0100
+++ b/src/HOL/Limits.thy	Wed Apr 02 16:45:31 2014 +0100
@@ -404,6 +404,10 @@
 lemma tendsto_Zfun_iff: "(f ---> a) F = Zfun (\<lambda>x. f x - a) F"
   by (simp only: tendsto_iff Zfun_def dist_norm)
 
+lemma tendsto_0_le: "\<lbrakk>(f ---> 0) F; eventually (\<lambda>x. norm (g x) \<le> norm (f x) * K) F\<rbrakk> 
+                     \<Longrightarrow> (g ---> 0) F"
+  by (simp add: Zfun_imp_Zfun tendsto_Zfun_iff)
+
 subsubsection {* Distance and norms *}
 
 lemma tendsto_dist [tendsto_intros]: