(* Title: HOL/UNITY/Lift_prog.thy
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1999 University of Cambridge
lift_prog, etc: replication of components
*)
Lift_prog = Project +
constdefs
lift_map :: "['a, 'b * ('a => 'b)] => ('a => 'b)"
"lift_map i == %(s,f). f(i := s)"
lift_set :: "['a, 'b set] => ('a => 'b) set"
"lift_set i A == {f. f i : A}"
drop_set :: "['a, ('a=>'b) set] => 'b set"
"drop_set i A == (%f. f i) `` A"
lift_act :: "['a, ('b*'b) set] => (('a=>'b) * ('a=>'b)) set"
"lift_act i act == {(f,f'). f(i:= f' i) = f' & (f i, f' i) : act}"
(*Argument C allows weak safety laws to be projected*)
drop_act :: "[('a=>'b) set, 'a, (('a=>'b) * ('a=>'b)) set] => ('b*'b) set"
"drop_act C i act == {(f i, f' i) | f f'. (f,f'): act & f: C}"
lift_prog :: "['a, 'b program] => ('a => 'b) program"
"lift_prog i F ==
mk_program (lift_set i (Init F),
lift_act i `` Acts F)"
drop_prog :: "[('a=>'b) set, 'a, ('a=>'b) program] => 'b program"
"drop_prog C i F ==
mk_program (drop_set i (Init F),
drop_act C i `` (Acts F))"
(*simplifies the expression of specifications*)
constdefs
sub :: ['a, 'a=>'b] => 'b
"sub i f == f i"
end