src/ZF/AC/first.thy
author clasohm
Tue Feb 06 12:27:17 1996 +0100 (1996-02-06)
changeset 1478 2b8c2a7547ab
parent 1401 0c439768f45c
permissions -rw-r--r--
expanded tabs
     1 (*  Title:      ZF/AC/first.thy
     2     ID:         $Id$
     3     Author:     Krzysztof Grabczewski
     4 
     5 Theory helpful in proofs using first element of a well ordered set
     6 *)
     7 
     8 first = Order +
     9 
    10 consts
    11 
    12   first                   :: [i, i, i] => o
    13 
    14 defs
    15 
    16   first_def                "first(u, X, R) 
    17                             == u:X & (ALL v:X. v~=u --> <u,v> : R)"
    18 end