src/HOL/UNITY/Comp.thy
author paulson
Thu Oct 01 18:28:47 1998 +0200 (1998-10-01)
changeset 5597 a12b25c53df1
child 5612 e981ca6f7332
permissions -rw-r--r--
composition theory
     1 (*  Title:      HOL/UNITY/Comp.thy
     2     ID:         $Id$
     3     Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
     4     Copyright   1998  University of Cambridge
     5 
     6 Composition
     7 
     8 From Chandy and Sanders, "Reasoning About Program Composition"
     9 *)
    10 
    11 Comp = Union +
    12 
    13 constdefs
    14 
    15   (*Existential and Universal properties.  I formalize the two-program
    16     case, proving equivalence with Chandy and Sanders's n-ary definitions*)
    17 
    18   ex_prop  :: 'a program set => bool
    19    "ex_prop X == ALL F G. F:X | G: X --> (Join F G) : X"
    20 
    21   strict_ex_prop  :: 'a program set => bool
    22    "strict_ex_prop X == ALL F G. (F:X | G: X) = (Join F G : X)"
    23 
    24   uv_prop  :: 'a program set => bool
    25    "uv_prop X == SKIP: X & (ALL F G. F:X & G: X --> (Join F G) : X)"
    26 
    27   strict_uv_prop  :: 'a program set => bool
    28    "strict_uv_prop X == SKIP: X & (ALL F G. (F:X & G: X) = (Join F G : X))"
    29 
    30   compatible :: ['a program, 'a program] => bool
    31    "compatible F G == Init F Int Init G ~= {}"
    32 
    33   component :: ['a program, 'a program] => bool
    34    "component F H == EX G. Join F G = H"
    35 
    36   guarantees :: ['a program set, 'a program set] => 'a program set (infixl 65)
    37    "X guarantees Y == {F. ALL H. component F H --> H:X --> H:Y}"
    38 
    39 end