src/HOL/Probability/Borel_Space.thy
changeset 50419 3177d0374701
parent 50387 3d8863c41fe8
child 50526 899c9c4e4a4c
equal deleted inserted replaced
50418:bd68cf816dd3 50419:3177d0374701
   813 qed
   813 qed
   814 
   814 
   815 lemma borel_measurable_log[measurable (raw)]:
   815 lemma borel_measurable_log[measurable (raw)]:
   816   "f \<in> borel_measurable M \<Longrightarrow> g \<in> borel_measurable M \<Longrightarrow> (\<lambda>x. log (g x) (f x)) \<in> borel_measurable M"
   816   "f \<in> borel_measurable M \<Longrightarrow> g \<in> borel_measurable M \<Longrightarrow> (\<lambda>x. log (g x) (f x)) \<in> borel_measurable M"
   817   unfolding log_def by auto
   817   unfolding log_def by auto
       
   818 
       
   819 lemma borel_measurable_exp[measurable]: "exp \<in> borel_measurable borel"
       
   820   by (intro borel_measurable_continuous_on1 continuous_at_imp_continuous_on ballI
       
   821             continuous_isCont[THEN iffD1] isCont_exp)
   818 
   822 
   819 lemma measurable_count_space_eq2_countable:
   823 lemma measurable_count_space_eq2_countable:
   820   fixes f :: "'a => 'c::countable"
   824   fixes f :: "'a => 'c::countable"
   821   shows "f \<in> measurable M (count_space A) \<longleftrightarrow> (f \<in> space M \<rightarrow> A \<and> (\<forall>a\<in>A. f -` {a} \<inter> space M \<in> sets M))"
   825   shows "f \<in> measurable M (count_space A) \<longleftrightarrow> (f \<in> space M \<rightarrow> A \<and> (\<forall>a\<in>A. f -` {a} \<inter> space M \<in> sets M))"
   822 proof -
   826 proof -