src/HOL/Set.thy
changeset 13103 66659a4b16f6
parent 12937 0c4fd7529467
child 13113 5eb9be7b72a5
equal deleted inserted replaced
13102:b6f8aae5f152 13103:66659a4b16f6
  1047   by auto
  1047   by auto
  1048 
  1048 
  1049 lemma UN_insert_distrib: "u \<in> A ==> (\<Union>x\<in>A. insert a (B x)) = insert a (\<Union>x\<in>A. B x)"
  1049 lemma UN_insert_distrib: "u \<in> A ==> (\<Union>x\<in>A. insert a (B x)) = insert a (\<Union>x\<in>A. B x)"
  1050   by blast
  1050   by blast
  1051 
  1051 
       
  1052 lemma insert_disjoint[simp]:
       
  1053  "(insert a A \<inter> B = {}) = (a \<notin> B \<and> A \<inter> B = {})"
       
  1054 by blast
       
  1055 
       
  1056 lemma disjoint_insert[simp]:
       
  1057  "(B \<inter> insert a A = {}) = (a \<notin> B \<and> B \<inter> A = {})"
       
  1058 by blast
  1052 
  1059 
  1053 text {* \medskip @{text image}. *}
  1060 text {* \medskip @{text image}. *}
  1054 
  1061 
  1055 lemma image_empty [simp]: "f`{} = {}"
  1062 lemma image_empty [simp]: "f`{} = {}"
  1056   by blast
  1063   by blast