src/HOLCF/dnat2.thy
author paulson
Fri, 08 Dec 1995 10:39:52 +0100
changeset 1394 a1d2735f5ade
parent 243 c22b85994e17
permissions -rw-r--r--
New function read_cterms is a combination of read_def_cterm and read_cterm. It reads and simultaneously type-checks a list of strings. cterm_of no longer catches exception TYPE; instead it must be caught later on and a message printed using Sign.exn_type_msg. More informative messages can be printed this way.

(*  Title: 	HOLCF/dnat2.thy
    ID:         $Id$
    Author: 	Franz Regensburger
    Copyright   1993 Technische Universitaet Muenchen

Additional constants for dnat

*)

Dnat2 = Dnat +

consts

iterator	:: "dnat -> ('a -> 'a) -> 'a -> 'a"


rules

iterator_def	"iterator = fix[LAM h n f x.\
\	dnat_when[x][LAM m.f[h[m][f][x]]][n]]"


end


(*

		iterator[UU][f][x] = UU
		iterator[dzero][f][x] = x
      n~=UU --> iterator[dsucc[n]][f][x] = f[iterator[n][f][x]]
*)