src/HOLCF/ex/Stream.thy
changeset 18109 94b528311e22
parent 18075 43000d7a017c
child 19440 b2877e230b07
equal deleted inserted replaced
18108:1e4516e68a58 18109:94b528311e22
    69 by auto
    69 by auto
    70 
    70 
    71 lemma stream_exhaust_eq: "(x ~= UU) = (EX a y. a ~= UU &  x = a && y)"
    71 lemma stream_exhaust_eq: "(x ~= UU) = (EX a y. a ~= UU &  x = a && y)"
    72 by (auto,insert stream.exhaust [of x],auto)
    72 by (auto,insert stream.exhaust [of x],auto)
    73 
    73 
    74 lemma stream_neq_UU: "x~=UU ==> EX a as. x=a&&as & a~=UU"
    74 lemma stream_neq_UU: "x~=UU ==> EX a a_s. x=a&&a_s & a~=UU"
    75 by (simp add: stream_exhaust_eq,auto)
    75 by (simp add: stream_exhaust_eq,auto)
    76 
    76 
    77 lemma stream_inject_eq [simp]:
    77 lemma stream_inject_eq [simp]:
    78   "[| a ~= UU; b ~= UU |] ==> (a && s = b && t) = (a = b &  s = t)"
    78   "[| a ~= UU; b ~= UU |] ==> (a && s = b && t) = (a = b &  s = t)"
    79 by (insert stream.injects [of a s b t], auto)
    79 by (insert stream.injects [of a s b t], auto)