src/ZF/Epsilon.thy
author paulson
Fri, 16 Feb 1996 18:00:47 +0100
changeset 1512 ce37c64244c0
parent 1478 2b8c2a7547ab
child 2469 b50b8c0eec01
permissions -rw-r--r--
Elimination of fully-functorial style. Type tactic changed to a type abbrevation (from a datatype). Constructor tactic and function apply deleted.

(*  Title:      ZF/epsilon.thy
    ID:         $Id$
    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
    Copyright   1993  University of Cambridge

Epsilon induction and recursion
*)

Epsilon = Nat + "mono" +
consts
    eclose,rank ::      i=>i
    transrec    ::      [i, [i,i]=>i] =>i

defs
  eclose_def    "eclose(A) == UN n:nat. nat_rec(n, A, %m r. Union(r))"
  transrec_def  "transrec(a,H) == wfrec(Memrel(eclose({a})), a, H)"
  rank_def      "rank(a) == transrec(a, %x f. UN y:x. succ(f`y))"
end