(* Title: HOL/UNITY/Project.ML
ID: $Id$
Author: Lawrence C Paulson, Cambridge University Computer Laboratory
Copyright 1999 University of Cambridge
Projections of state sets (also of actions and programs)
Inheritance of GUARANTEES properties under extension
*)
Project = Extend +
constdefs
projecting :: "['c program => 'c set, 'a*'b => 'c,
'a program, 'c program set, 'a program set] => bool"
"projecting C h F X' X ==
ALL G. extend h F Join G : X' --> F Join project h (C G) G : X"
extending :: "['c=>'d, 'c program => 'c set, 'a*'b => 'c, 'a program,
'c program set, 'a program set] => bool"
"extending v C h F Y' Y ==
ALL G. G : preserves v --> F Join project h (C G) G : Y
--> extend h F Join G : Y'"
end