809 |
809 |
810 lemma%important borel_measurable_SUP[measurable (raw)]: |
810 lemma%important borel_measurable_SUP[measurable (raw)]: |
811 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> _::{complete_linorder, linorder_topology, second_countable_topology}" |
811 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> _::{complete_linorder, linorder_topology, second_countable_topology}" |
812 assumes [simp]: "countable I" |
812 assumes [simp]: "countable I" |
813 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
813 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
814 shows "(\<lambda>x. SUP i:I. F i x) \<in> borel_measurable M" |
814 shows "(\<lambda>x. SUP i\<in>I. F i x) \<in> borel_measurable M" |
815 by%unimportant (rule borel_measurableI_greater) (simp add: less_SUP_iff) |
815 by%unimportant (rule borel_measurableI_greater) (simp add: less_SUP_iff) |
816 |
816 |
817 lemma%unimportant borel_measurable_INF[measurable (raw)]: |
817 lemma%unimportant borel_measurable_INF[measurable (raw)]: |
818 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> _::{complete_linorder, linorder_topology, second_countable_topology}" |
818 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> _::{complete_linorder, linorder_topology, second_countable_topology}" |
819 assumes [simp]: "countable I" |
819 assumes [simp]: "countable I" |
820 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
820 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
821 shows "(\<lambda>x. INF i:I. F i x) \<in> borel_measurable M" |
821 shows "(\<lambda>x. INF i\<in>I. F i x) \<in> borel_measurable M" |
822 by (rule borel_measurableI_less) (simp add: INF_less_iff) |
822 by (rule borel_measurableI_less) (simp add: INF_less_iff) |
823 |
823 |
824 lemma%unimportant borel_measurable_cSUP[measurable (raw)]: |
824 lemma%unimportant borel_measurable_cSUP[measurable (raw)]: |
825 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> 'a::{conditionally_complete_linorder, linorder_topology, second_countable_topology}" |
825 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> 'a::{conditionally_complete_linorder, linorder_topology, second_countable_topology}" |
826 assumes [simp]: "countable I" |
826 assumes [simp]: "countable I" |
827 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
827 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
828 assumes bdd: "\<And>x. x \<in> space M \<Longrightarrow> bdd_above ((\<lambda>i. F i x) ` I)" |
828 assumes bdd: "\<And>x. x \<in> space M \<Longrightarrow> bdd_above ((\<lambda>i. F i x) ` I)" |
829 shows "(\<lambda>x. SUP i:I. F i x) \<in> borel_measurable M" |
829 shows "(\<lambda>x. SUP i\<in>I. F i x) \<in> borel_measurable M" |
830 proof cases |
830 proof cases |
831 assume "I = {}" then show ?thesis |
831 assume "I = {}" then show ?thesis |
832 unfolding \<open>I = {}\<close> image_empty by simp |
832 unfolding \<open>I = {}\<close> image_empty by simp |
833 next |
833 next |
834 assume "I \<noteq> {}" |
834 assume "I \<noteq> {}" |
835 show ?thesis |
835 show ?thesis |
836 proof (rule borel_measurableI_le) |
836 proof (rule borel_measurableI_le) |
837 fix y |
837 fix y |
838 have "{x \<in> space M. \<forall>i\<in>I. F i x \<le> y} \<in> sets M" |
838 have "{x \<in> space M. \<forall>i\<in>I. F i x \<le> y} \<in> sets M" |
839 by measurable |
839 by measurable |
840 also have "{x \<in> space M. \<forall>i\<in>I. F i x \<le> y} = {x \<in> space M. (SUP i:I. F i x) \<le> y}" |
840 also have "{x \<in> space M. \<forall>i\<in>I. F i x \<le> y} = {x \<in> space M. (SUP i\<in>I. F i x) \<le> y}" |
841 by (simp add: cSUP_le_iff \<open>I \<noteq> {}\<close> bdd cong: conj_cong) |
841 by (simp add: cSUP_le_iff \<open>I \<noteq> {}\<close> bdd cong: conj_cong) |
842 finally show "{x \<in> space M. (SUP i:I. F i x) \<le> y} \<in> sets M" . |
842 finally show "{x \<in> space M. (SUP i\<in>I. F i x) \<le> y} \<in> sets M" . |
843 qed |
843 qed |
844 qed |
844 qed |
845 |
845 |
846 lemma%important borel_measurable_cINF[measurable (raw)]: |
846 lemma%important borel_measurable_cINF[measurable (raw)]: |
847 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> 'a::{conditionally_complete_linorder, linorder_topology, second_countable_topology}" |
847 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> 'a::{conditionally_complete_linorder, linorder_topology, second_countable_topology}" |
848 assumes [simp]: "countable I" |
848 assumes [simp]: "countable I" |
849 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
849 assumes [measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
850 assumes bdd: "\<And>x. x \<in> space M \<Longrightarrow> bdd_below ((\<lambda>i. F i x) ` I)" |
850 assumes bdd: "\<And>x. x \<in> space M \<Longrightarrow> bdd_below ((\<lambda>i. F i x) ` I)" |
851 shows "(\<lambda>x. INF i:I. F i x) \<in> borel_measurable M" |
851 shows "(\<lambda>x. INF i\<in>I. F i x) \<in> borel_measurable M" |
852 proof%unimportant cases |
852 proof%unimportant cases |
853 assume "I = {}" then show ?thesis |
853 assume "I = {}" then show ?thesis |
854 unfolding \<open>I = {}\<close> image_empty by simp |
854 unfolding \<open>I = {}\<close> image_empty by simp |
855 next |
855 next |
856 assume "I \<noteq> {}" |
856 assume "I \<noteq> {}" |
857 show ?thesis |
857 show ?thesis |
858 proof (rule borel_measurableI_ge) |
858 proof (rule borel_measurableI_ge) |
859 fix y |
859 fix y |
860 have "{x \<in> space M. \<forall>i\<in>I. y \<le> F i x} \<in> sets M" |
860 have "{x \<in> space M. \<forall>i\<in>I. y \<le> F i x} \<in> sets M" |
861 by measurable |
861 by measurable |
862 also have "{x \<in> space M. \<forall>i\<in>I. y \<le> F i x} = {x \<in> space M. y \<le> (INF i:I. F i x)}" |
862 also have "{x \<in> space M. \<forall>i\<in>I. y \<le> F i x} = {x \<in> space M. y \<le> (INF i\<in>I. F i x)}" |
863 by (simp add: le_cINF_iff \<open>I \<noteq> {}\<close> bdd cong: conj_cong) |
863 by (simp add: le_cINF_iff \<open>I \<noteq> {}\<close> bdd cong: conj_cong) |
864 finally show "{x \<in> space M. y \<le> (INF i:I. F i x)} \<in> sets M" . |
864 finally show "{x \<in> space M. y \<le> (INF i\<in>I. F i x)} \<in> sets M" . |
865 qed |
865 qed |
866 qed |
866 qed |
867 |
867 |
868 lemma%unimportant borel_measurable_lfp[consumes 1, case_names continuity step]: |
868 lemma%unimportant borel_measurable_lfp[consumes 1, case_names continuity step]: |
869 fixes F :: "('a \<Rightarrow> 'b) \<Rightarrow> ('a \<Rightarrow> 'b::{complete_linorder, linorder_topology, second_countable_topology})" |
869 fixes F :: "('a \<Rightarrow> 'b) \<Rightarrow> ('a \<Rightarrow> 'b::{complete_linorder, linorder_topology, second_countable_topology})" |
1956 |
1956 |
1957 lemma%important borel_measurable_cINF_real[measurable (raw)]: |
1957 lemma%important borel_measurable_cINF_real[measurable (raw)]: |
1958 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> real" |
1958 fixes F :: "_ \<Rightarrow> _ \<Rightarrow> real" |
1959 assumes [simp]: "countable I" |
1959 assumes [simp]: "countable I" |
1960 assumes F[measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
1960 assumes F[measurable]: "\<And>i. i \<in> I \<Longrightarrow> F i \<in> borel_measurable M" |
1961 shows "(\<lambda>x. INF i:I. F i x) \<in> borel_measurable M" |
1961 shows "(\<lambda>x. INF i\<in>I. F i x) \<in> borel_measurable M" |
1962 proof%unimportant (rule measurable_piecewise_restrict) |
1962 proof%unimportant (rule measurable_piecewise_restrict) |
1963 let ?\<Omega> = "{x\<in>space M. bdd_below ((\<lambda>i. F i x)`I)}" |
1963 let ?\<Omega> = "{x\<in>space M. bdd_below ((\<lambda>i. F i x)`I)}" |
1964 show "countable {?\<Omega>, - ?\<Omega>}" "space M \<subseteq> \<Union>{?\<Omega>, - ?\<Omega>}" "\<And>X. X \<in> {?\<Omega>, - ?\<Omega>} \<Longrightarrow> X \<inter> space M \<in> sets M" |
1964 show "countable {?\<Omega>, - ?\<Omega>}" "space M \<subseteq> \<Union>{?\<Omega>, - ?\<Omega>}" "\<And>X. X \<in> {?\<Omega>, - ?\<Omega>} \<Longrightarrow> X \<inter> space M \<in> sets M" |
1965 by auto |
1965 by auto |
1966 fix X assume "X \<in> {?\<Omega>, - ?\<Omega>}" then show "(\<lambda>x. INF i:I. F i x) \<in> borel_measurable (restrict_space M X)" |
1966 fix X assume "X \<in> {?\<Omega>, - ?\<Omega>}" then show "(\<lambda>x. INF i\<in>I. F i x) \<in> borel_measurable (restrict_space M X)" |
1967 proof safe |
1967 proof safe |
1968 show "(\<lambda>x. INF i:I. F i x) \<in> borel_measurable (restrict_space M ?\<Omega>)" |
1968 show "(\<lambda>x. INF i\<in>I. F i x) \<in> borel_measurable (restrict_space M ?\<Omega>)" |
1969 by (intro borel_measurable_cINF measurable_restrict_space1 F) |
1969 by (intro borel_measurable_cINF measurable_restrict_space1 F) |
1970 (auto simp: space_restrict_space) |
1970 (auto simp: space_restrict_space) |
1971 show "(\<lambda>x. INF i:I. F i x) \<in> borel_measurable (restrict_space M (-?\<Omega>))" |
1971 show "(\<lambda>x. INF i\<in>I. F i x) \<in> borel_measurable (restrict_space M (-?\<Omega>))" |
1972 proof (subst measurable_cong) |
1972 proof (subst measurable_cong) |
1973 fix x assume "x \<in> space (restrict_space M (-?\<Omega>))" |
1973 fix x assume "x \<in> space (restrict_space M (-?\<Omega>))" |
1974 then have "\<not> (\<forall>i\<in>I. - F i x \<le> y)" for y |
1974 then have "\<not> (\<forall>i\<in>I. - F i x \<le> y)" for y |
1975 by (auto simp: space_restrict_space bdd_above_def bdd_above_uminus[symmetric]) |
1975 by (auto simp: space_restrict_space bdd_above_def bdd_above_uminus[symmetric]) |
1976 then show "(INF i:I. F i x) = - (THE x. False)" |
1976 then show "(INF i\<in>I. F i x) = - (THE x. False)" |
1977 by (auto simp: space_restrict_space Inf_real_def Sup_real_def Least_def simp del: Set.ball_simps(10)) |
1977 by (auto simp: space_restrict_space Inf_real_def Sup_real_def Least_def simp del: Set.ball_simps(10)) |
1978 qed simp |
1978 qed simp |
1979 qed |
1979 qed |
1980 qed |
1980 qed |
1981 |
1981 |