src/HOL/Analysis/Elementary_Metric_Spaces.thy
changeset 73885 26171a89466a
parent 72569 d56e4eeae967
child 73933 fa92bc604c59
equal deleted inserted replaced
73884:0a12ca4f3e8d 73885:26171a89466a
  1462 lemma compact_eq_bounded_closed:
  1462 lemma compact_eq_bounded_closed:
  1463   fixes S :: "'a::heine_borel set"
  1463   fixes S :: "'a::heine_borel set"
  1464   shows "compact S \<longleftrightarrow> bounded S \<and> closed S"
  1464   shows "compact S \<longleftrightarrow> bounded S \<and> closed S"
  1465   using bounded_closed_imp_seq_compact compact_eq_seq_compact_metric compact_imp_bounded compact_imp_closed 
  1465   using bounded_closed_imp_seq_compact compact_eq_seq_compact_metric compact_imp_bounded compact_imp_closed 
  1466   by auto
  1466   by auto
       
  1467 
       
  1468 lemma bounded_infinite_imp_islimpt:
       
  1469   fixes S :: "'a::heine_borel set"
       
  1470   assumes "T \<subseteq> S" "bounded S" "infinite T"
       
  1471   obtains x where "x islimpt S" 
       
  1472   by (meson assms closed_limpt compact_eq_Bolzano_Weierstrass compact_eq_bounded_closed islimpt_subset) 
  1467 
  1473 
  1468 lemma compact_Inter:
  1474 lemma compact_Inter:
  1469   fixes \<F> :: "'a :: heine_borel set set"
  1475   fixes \<F> :: "'a :: heine_borel set set"
  1470   assumes com: "\<And>S. S \<in> \<F> \<Longrightarrow> compact S" and "\<F> \<noteq> {}"
  1476   assumes com: "\<And>S. S \<in> \<F> \<Longrightarrow> compact S" and "\<F> \<noteq> {}"
  1471   shows "compact(\<Inter> \<F>)"
  1477   shows "compact(\<Inter> \<F>)"