src/CTT/bool.thy
author wenzelm
Mon, 12 Jul 1999 22:27:20 +0200
changeset 6981 eaade7e398a7
parent 0 a5a9c433f639
permissions -rw-r--r--
export assumption_tac; local qeds: print rule; same_tac: actually insert rules, !! bind vars;

(*  Title: 	CTT/bool
    ID:         $Id$
    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1991  University of Cambridge

The two-element type (booleans and conditionals)
*)

Bool = CTT +

consts Bool		:: "t"
       true,false	:: "i"
       cond		:: "[i,i,i]=>i"
rules
  Bool_def	"Bool == T+T"
  true_def	"true == inl(tt)"
  false_def	"false == inr(tt)"
  cond_def	"cond(a,b,c) == when(a, %u.b, %u.c)"
end