(* Title: HOLCF/FOCUS/Fstream.thy
ID: $Id$
Author: David von Oheimb, TU Muenchen
License: GPL (GNU GENERAL PUBLIC LICENSE)
FOCUS streams (with lifted elements)
*)
(* FOCUS flat streams *)
Fstream = Stream +
default type
types 'a fstream = ('a lift) stream
consts
fscons :: "'a \\<Rightarrow> 'a fstream \\<rightarrow> 'a fstream"
fsfilter :: "'a set \\<Rightarrow> 'a fstream \\<rightarrow> 'a fstream"
syntax
"@emptystream":: "'a fstream" ("<>")
"@fscons" :: "'a \\<Rightarrow> 'a fstream \\<Rightarrow> 'a fstream" ("(_~>_)" [66,65] 65)
"@fsfilter" :: "'a set \\<Rightarrow> 'a fstream \\<Rightarrow> 'a fstream" ("(_'(C')_)" [64,63] 63)
syntax (xsymbols)
"@fscons" :: "'a \\<Rightarrow> 'a fstream \\<Rightarrow> 'a fstream" ("(_\\<leadsto>_)"
[66,65] 65)
"@fsfilter" :: "'a set \\<Rightarrow> 'a fstream \\<Rightarrow> 'a fstream" ("(_\\<copyright>_)"
[64,63] 63)
translations
"<>" => "\\<bottom>"
"a~>s" == "fscons a\\<cdot>s"
"A(C)s" == "fsfilter A\\<cdot>s"
defs
fscons_def "fscons a \\<equiv> \\<Lambda>s. Def a && s"
fsfilter_def "fsfilter A \\<equiv> sfilter\\<cdot>(flift2 (\\<lambda>x. x\\<in>A))"
end