src/HOL/UNITY/Comp.thy
author berghofe
Thu, 07 Oct 1999 15:40:32 +0200
changeset 7786 cf9d07ad62af
parent 7399 cf780c2bcccf
child 8055 bb15396278fb
permissions -rw-r--r--
Replaced update_new by update.

(*  Title:      HOL/UNITY/Comp.thy
    ID:         $Id$
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1998  University of Cambridge

Composition

From Chandy and Sanders, "Reasoning About Program Composition"
*)

Comp = Union +

instance
  program :: (term)ord

defs

  component_def   "F <= H == EX G. F Join G = H"

  strict_component_def   "(F < (H::'a program)) == (F <= H & F ~= H)"

end