src/ZF/Perm.thy
changeset 63901 4ce989e962e0
parent 60770 240563fbf41d
child 67399 eab6ce8368fa
equal deleted inserted replaced
63899:dc036b1a2a6f 63901:4ce989e962e0
   135      |] ==> (\<lambda>x\<in>A. c(x)) \<in> bij(A,B)"
   135      |] ==> (\<lambda>x\<in>A. c(x)) \<in> bij(A,B)"
   136 apply (unfold bij_def)
   136 apply (unfold bij_def)
   137 apply (blast intro!: lam_injective lam_surjective)
   137 apply (blast intro!: lam_injective lam_surjective)
   138 done
   138 done
   139 
   139 
   140 lemma RepFun_bijective: "(\<forall>y\<in>x. EX! y'. f(y') = f(y))
   140 lemma RepFun_bijective: "(\<forall>y\<in>x. \<exists>!y'. f(y') = f(y))
   141       ==> (\<lambda>z\<in>{f(y). y \<in> x}. THE y. f(y) = z) \<in> bij({f(y). y \<in> x}, x)"
   141       ==> (\<lambda>z\<in>{f(y). y \<in> x}. THE y. f(y) = z) \<in> bij({f(y). y \<in> x}, x)"
   142 apply (rule_tac d = f in lam_bijective)
   142 apply (rule_tac d = f in lam_bijective)
   143 apply (auto simp add: the_equality2)
   143 apply (auto simp add: the_equality2)
   144 done
   144 done
   145 
   145