src/HOL/Analysis/Set_Integral.thy
changeset 66164 2d79288b042c
parent 64911 f0e07600de47
child 66447 a1f5c5c26fa6
equal deleted inserted replaced
66161:c6e9c7d140ff 66164:2d79288b042c
  1838 ("(4CLINT _:_|_. _)" [0,60,110,61] 60)
  1838 ("(4CLINT _:_|_. _)" [0,60,110,61] 60)
  1839 
  1839 
  1840 translations
  1840 translations
  1841 "CLINT x:A|M. f" == "CONST complex_set_lebesgue_integral M A (\<lambda>x. f)"
  1841 "CLINT x:A|M. f" == "CONST complex_set_lebesgue_integral M A (\<lambda>x. f)"
  1842 
  1842 
  1843 lemma set_borel_measurable_continuous:
       
  1844   fixes f :: "_ \<Rightarrow> _::real_normed_vector"
       
  1845   assumes "S \<in> sets borel" "continuous_on S f"
       
  1846   shows "set_borel_measurable borel S f"
       
  1847 proof -
       
  1848   have "(\<lambda>x. if x \<in> S then f x else 0) \<in> borel_measurable borel"
       
  1849     by (intro assms borel_measurable_continuous_on_if continuous_on_const)
       
  1850   also have "(\<lambda>x. if x \<in> S then f x else 0) = (\<lambda>x. indicator S x *\<^sub>R f x)"
       
  1851     by auto
       
  1852   finally show ?thesis .
       
  1853 qed
       
  1854 
       
  1855 lemma set_measurable_continuous_on_ivl:
  1843 lemma set_measurable_continuous_on_ivl:
  1856   assumes "continuous_on {a..b} (f :: real \<Rightarrow> real)"
  1844   assumes "continuous_on {a..b} (f :: real \<Rightarrow> real)"
  1857   shows "set_borel_measurable borel {a..b} f"
  1845   shows "set_borel_measurable borel {a..b} f"
  1858   by (rule set_borel_measurable_continuous[OF _ assms]) simp
  1846   by (rule borel_measurable_continuous_on_indicator[OF _ assms]) simp
  1859 
  1847 
  1860 
  1848 
  1861 text\<open>This notation is from Sébastien Gouëzel: His use is not directly in line with the
  1849 text\<open>This notation is from Sébastien Gouëzel: His use is not directly in line with the
  1862 notations in this file, they are more in line with sum, and more readable he thinks.\<close>
  1850 notations in this file, they are more in line with sum, and more readable he thinks.\<close>
  1863 
  1851