equal
deleted
inserted
replaced
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 |
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1467 |
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1468 lemma bounded_infinite_imp_islimpt: |
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1469 fixes S :: "'a::heine_borel set" |
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1470 assumes "T \<subseteq> S" "bounded S" "infinite T" |
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1471 obtains x where "x islimpt S" |
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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>)" |