src/HOL/Analysis/Linear_Algebra.thy
changeset 66447 a1f5c5c26fa6
parent 66420 bc0dab0e7b40
child 66453 cc19f7ca2ed6
equal deleted inserted replaced
66445:407de0768126 66447:a1f5c5c26fa6
  1755   apply auto
  1755   apply auto
  1756   done
  1756   done
  1757 
  1757 
  1758 lemma infinite_enumerate:
  1758 lemma infinite_enumerate:
  1759   assumes fS: "infinite S"
  1759   assumes fS: "infinite S"
  1760   shows "\<exists>r. subseq r \<and> (\<forall>n. r n \<in> S)"
  1760   shows "\<exists>r::nat\<Rightarrow>nat. strict_mono r \<and> (\<forall>n. r n \<in> S)"
  1761   unfolding subseq_def
  1761   unfolding strict_mono_def
  1762   using enumerate_in_set[OF fS] enumerate_mono[of _ _ S] fS by auto
  1762   using enumerate_in_set[OF fS] enumerate_mono[of _ _ S] fS by auto
  1763 
  1763 
  1764 lemma approachable_lt_le: "(\<exists>(d::real) > 0. \<forall>x. f x < d \<longrightarrow> P x) \<longleftrightarrow> (\<exists>d>0. \<forall>x. f x \<le> d \<longrightarrow> P x)"
  1764 lemma approachable_lt_le: "(\<exists>(d::real) > 0. \<forall>x. f x < d \<longrightarrow> P x) \<longleftrightarrow> (\<exists>d>0. \<forall>x. f x \<le> d \<longrightarrow> P x)"
  1765   apply auto
  1765   apply auto
  1766   apply (rule_tac x="d/2" in exI)
  1766   apply (rule_tac x="d/2" in exI)