src/HOL/Analysis/Nonnegative_Lebesgue_Integration.thy
changeset 66804 3f9bb52082c4
parent 65680 378a2f11bec9
child 67399 eab6ce8368fa
equal deleted inserted replaced
66803:dd8922885a68 66804:3f9bb52082c4
   646   qed
   646   qed
   647   also have "\<dots> = (\<Sum>y\<in>f`space M. (\<Sum>z\<in>g`space M.
   647   also have "\<dots> = (\<Sum>y\<in>f`space M. (\<Sum>z\<in>g`space M.
   648       if \<exists>x\<in>space M. y = f x \<and> z = g x then y * emeasure M {x\<in>space M. g x = z} else 0))"
   648       if \<exists>x\<in>space M. y = f x \<and> z = g x then y * emeasure M {x\<in>space M. g x = z} else 0))"
   649     by (auto intro!: sum.cong simp: sum_distrib_left)
   649     by (auto intro!: sum.cong simp: sum_distrib_left)
   650   also have "\<dots> = ?r"
   650   also have "\<dots> = ?r"
   651     by (subst sum.commute)
   651     by (subst sum.swap)
   652        (auto intro!: sum.cong simp: sum.If_cases scaleR_sum_right[symmetric] eq)
   652        (auto intro!: sum.cong simp: sum.If_cases scaleR_sum_right[symmetric] eq)
   653   finally show "integral\<^sup>S M f = ?r" .
   653   finally show "integral\<^sup>S M f = ?r" .
   654 qed
   654 qed
   655 
   655 
   656 lemma simple_integral_add[simp]:
   656 lemma simple_integral_add[simp]: