src/HOL/Probability/Measure.thy
changeset 44928 7ef6505bde7f
parent 44890 22f665a2e91c
child 45342 5c760e1692b3
equal deleted inserted replaced
44927:8bf41f8cf71d 44928:7ef6505bde7f
   588 qed simp_all
   588 qed simp_all
   589 
   589 
   590 lemma UN_from_nat: "(\<Union>i. N i) = (\<Union>i. N (Countable.from_nat i))"
   590 lemma UN_from_nat: "(\<Union>i. N i) = (\<Union>i. N (Countable.from_nat i))"
   591 proof -
   591 proof -
   592   have "(\<Union>i. N i) = (\<Union>i. (N \<circ> Countable.from_nat) i)"
   592   have "(\<Union>i. N i) = (\<Union>i. (N \<circ> Countable.from_nat) i)"
   593     unfolding SUPR_def image_compose
   593     unfolding SUP_def image_compose
   594     unfolding surj_from_nat ..
   594     unfolding surj_from_nat ..
   595   then show ?thesis by simp
   595   then show ?thesis by simp
   596 qed
   596 qed
   597 
   597 
   598 lemma (in measure_space) null_sets_UN[intro]:
   598 lemma (in measure_space) null_sets_UN[intro]: