src/HOL/IMP/Procs.thy
author wenzelm
Sun, 20 May 2012 11:34:33 +0200
changeset 47884 21c42b095c84
parent 47818 151d137f1095
child 51019 146f63c3f024
permissions -rw-r--r--
try to avoid races again (cf. 8c37cb84065f and fd3a36e48b09);

header "Extensions and Variations of IMP"

theory Procs imports BExp begin

subsection "Procedures and Local Variables"

type_synonym pname = string

datatype
  com = SKIP 
      | Assign vname aexp        ("_ ::= _" [1000, 61] 61)
      | Seq    com  com          ("_;/ _"  [60, 61] 60)
      | If     bexp com com     ("(IF _/ THEN _/ ELSE _)"  [0, 0, 61] 61)
      | While  bexp com         ("(WHILE _/ DO _)"  [0, 61] 61)
      | Var    vname com        ("(1{VAR _;;/ _})")
      | Proc   pname com com    ("(1{PROC _ = _;;/ _})")
      | CALL   pname

definition "test_com =
{VAR ''x'';;
 ''x'' ::= N 0;
 {PROC ''p'' = ''x'' ::= Plus (V ''x'') (V ''x'');;
  {PROC ''q'' = CALL ''p'';;
   {VAR ''x'';;
    ''x'' ::= N 5;
    {PROC ''p'' = ''x'' ::= Plus (V ''x'') (N 1);;
     CALL ''q''; ''y'' ::= V ''x''}}}}}"

end