src/HOL/Library/Product_Vector.thy
changeset 36661 0a5b7b818d65
parent 36660 1cc4ab4b7ff7
child 37678 0040bafffdef
equal deleted inserted replaced
36660:1cc4ab4b7ff7 36661:0a5b7b818d65
   310   show "eventually (\<lambda>x. (f x, g x) \<in> S) net"
   310   show "eventually (\<lambda>x. (f x, g x) \<in> S) net"
   311     by (rule eventually_elim2)
   311     by (rule eventually_elim2)
   312        (simp add: subsetD [OF `A \<times> B \<subseteq> S`])
   312        (simp add: subsetD [OF `A \<times> B \<subseteq> S`])
   313 qed
   313 qed
   314 
   314 
   315 lemma LIM_fst: "f -- x --> a \<Longrightarrow> (\<lambda>x. fst (f x)) -- x --> fst a"
       
   316 unfolding LIM_conv_tendsto by (rule tendsto_fst)
       
   317 
       
   318 lemma LIM_snd: "f -- x --> a \<Longrightarrow> (\<lambda>x. snd (f x)) -- x --> snd a"
       
   319 unfolding LIM_conv_tendsto by (rule tendsto_snd)
       
   320 
       
   321 lemma LIM_Pair:
       
   322   assumes "f -- x --> a" and "g -- x --> b"
       
   323   shows "(\<lambda>x. (f x, g x)) -- x --> (a, b)"
       
   324 using assms unfolding LIM_conv_tendsto
       
   325 by (rule tendsto_Pair)
       
   326 
       
   327 lemma Cauchy_fst: "Cauchy X \<Longrightarrow> Cauchy (\<lambda>n. fst (X n))"
   315 lemma Cauchy_fst: "Cauchy X \<Longrightarrow> Cauchy (\<lambda>n. fst (X n))"
   328 unfolding Cauchy_def by (fast elim: le_less_trans [OF dist_fst_le])
   316 unfolding Cauchy_def by (fast elim: le_less_trans [OF dist_fst_le])
   329 
   317 
   330 lemma Cauchy_snd: "Cauchy X \<Longrightarrow> Cauchy (\<lambda>n. snd (X n))"
   318 lemma Cauchy_snd: "Cauchy X \<Longrightarrow> Cauchy (\<lambda>n. snd (X n))"
   331 unfolding Cauchy_def by (fast elim: le_less_trans [OF dist_snd_le])
   319 unfolding Cauchy_def by (fast elim: le_less_trans [OF dist_snd_le])
   346   then show "\<exists>n0. \<forall>m\<ge>n0. \<forall>n\<ge>n0. dist (X m, Y m) (X n, Y n) < r" ..
   334   then show "\<exists>n0. \<forall>m\<ge>n0. \<forall>n\<ge>n0. dist (X m, Y m) (X n, Y n) < r" ..
   347 qed
   335 qed
   348 
   336 
   349 lemma isCont_Pair [simp]:
   337 lemma isCont_Pair [simp]:
   350   "\<lbrakk>isCont f x; isCont g x\<rbrakk> \<Longrightarrow> isCont (\<lambda>x. (f x, g x)) x"
   338   "\<lbrakk>isCont f x; isCont g x\<rbrakk> \<Longrightarrow> isCont (\<lambda>x. (f x, g x)) x"
   351   unfolding isCont_def by (rule LIM_Pair)
   339   unfolding isCont_def by (rule tendsto_Pair)
   352 
   340 
   353 subsection {* Product is a complete metric space *}
   341 subsection {* Product is a complete metric space *}
   354 
   342 
   355 instance "*" :: (complete_space, complete_space) complete_space
   343 instance "*" :: (complete_space, complete_space) complete_space
   356 proof
   344 proof