--- a/src/HOL/While.thy Wed Oct 18 23:31:16 2000 +0200
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,28 +0,0 @@
-(* Title: HOL/While
- ID: $Id$
- Author: Tobias Nipkow
- Copyright 2000 TU Muenchen
-
-Defines a while-combinator "while" and proves
-a) an unrestricted unfolding law (even if while diverges!)
- (I got this idea from Wolfgang Goerigk)
-b) the invariant rule for reasoning about while
-*)
-
-While = Recdef +
-
-consts while_aux :: "('a => bool) * ('a => 'a) * 'a => 'a"
-recdef while_aux
- "same_fst (%b. True) (%b. same_fst (%c. True) (%c.
- {(t,s). b s & c s = t &
- ~(? f. f 0 = s & (!i. b(f i) & c(f i) = f(i+1)))}))"
-"while_aux(b,c,s) =
- (if (? f. f 0 = s & (!i. b(f i) & c(f i) = f(i+1)))
- then arbitrary
- else if b s then while_aux(b,c,c s) else s)"
-
-constdefs
- while :: "('a => bool) => ('a => 'a) => 'a => 'a"
-"while b c s == while_aux(b,c,s)"
-
-end