src/HOL/Probability/Bochner_Integration.thy
changeset 61810 3c5040d5694a
parent 61808 fc1556774cfe
child 61880 ff4d33058566
equal deleted inserted replaced
61809:81d34cf268d8 61810:3c5040d5694a
   725   fix s v
   725   fix s v
   726   assume [measurable]: "f \<in> borel_measurable M" and s: "\<And>i. simple_bochner_integrable M (s i)" and
   726   assume [measurable]: "f \<in> borel_measurable M" and s: "\<And>i. simple_bochner_integrable M (s i)" and
   727     lim_0: "(\<lambda>i. \<integral>\<^sup>+ x. ereal (norm (f x - s i x)) \<partial>M) ----> 0"
   727     lim_0: "(\<lambda>i. \<integral>\<^sup>+ x. ereal (norm (f x - s i x)) \<partial>M) ----> 0"
   728   from order_tendstoD[OF lim_0, of "\<infinity>"]
   728   from order_tendstoD[OF lim_0, of "\<infinity>"]
   729   obtain i where f_s_fin: "(\<integral>\<^sup>+ x. ereal (norm (f x - s i x)) \<partial>M) < \<infinity>"
   729   obtain i where f_s_fin: "(\<integral>\<^sup>+ x. ereal (norm (f x - s i x)) \<partial>M) < \<infinity>"
   730     by (metis (mono_tags, lifting) eventually_False_sequentially eventually_elim1
   730     by (metis (mono_tags, lifting) eventually_False_sequentially eventually_mono
   731               less_ereal.simps(4) zero_ereal_def)
   731               less_ereal.simps(4) zero_ereal_def)
   732 
   732 
   733   have [measurable]: "\<And>i. s i \<in> borel_measurable M"
   733   have [measurable]: "\<And>i. s i \<in> borel_measurable M"
   734     using s by (auto intro: borel_measurable_simple_function elim: simple_bochner_integrable.cases)
   734     using s by (auto intro: borel_measurable_simple_function elim: simple_bochner_integrable.cases)
   735 
   735 
  2415       fix x
  2415       fix x
  2416       from \<open>filterlim X at_top sequentially\<close> 
  2416       from \<open>filterlim X at_top sequentially\<close> 
  2417       have "eventually (\<lambda>n. x \<le> X n) sequentially"
  2417       have "eventually (\<lambda>n. x \<le> X n) sequentially"
  2418         unfolding filterlim_at_top_ge[where c=x] by auto
  2418         unfolding filterlim_at_top_ge[where c=x] by auto
  2419       then show "(\<lambda>n. indicator {..X n} x *\<^sub>R f x) ----> f x"
  2419       then show "(\<lambda>n. indicator {..X n} x *\<^sub>R f x) ----> f x"
  2420         by (intro Lim_eventually) (auto split: split_indicator elim!: eventually_elim1)
  2420         by (intro Lim_eventually) (auto split: split_indicator elim!: eventually_mono)
  2421     qed
  2421     qed
  2422     fix n show "AE x in M. norm (indicator {..X n} x *\<^sub>R f x) \<le> norm (f x)"
  2422     fix n show "AE x in M. norm (indicator {..X n} x *\<^sub>R f x) \<le> norm (f x)"
  2423       by (auto split: split_indicator)
  2423       by (auto split: split_indicator)
  2424   qed auto
  2424   qed auto
  2425 qed
  2425 qed