src/HOL/HOLCF/Pcpo.thy
changeset 80914 d97fdabd9e2b
parent 80768 c7723cc15de8
child 81101 8407b4c068e2
equal deleted inserted replaced
80913:46f59511b7bb 80914:d97fdabd9e2b
   134 
   134 
   135 class pcpo = cpo +
   135 class pcpo = cpo +
   136   assumes least: "\<exists>x. \<forall>y. x \<sqsubseteq> y"
   136   assumes least: "\<exists>x. \<forall>y. x \<sqsubseteq> y"
   137 begin
   137 begin
   138 
   138 
   139 definition bottom :: "'a"  ("\<bottom>")
   139 definition bottom :: "'a"  (\<open>\<bottom>\<close>)
   140   where "bottom = (THE x. \<forall>y. x \<sqsubseteq> y)"
   140   where "bottom = (THE x. \<forall>y. x \<sqsubseteq> y)"
   141 
   141 
   142 lemma minimal [iff]: "\<bottom> \<sqsubseteq> x"
   142 lemma minimal [iff]: "\<bottom> \<sqsubseteq> x"
   143   unfolding bottom_def
   143   unfolding bottom_def
   144   apply (rule the1I2)
   144   apply (rule the1I2)