src/ZF/ex/LListFn.thy
author lcp
Tue Aug 16 18:58:42 1994 +0200 (1994-08-16)
changeset 532 851df239ac8b
parent 120 09287f26bfb8
permissions -rw-r--r--
ZF/Makefile,ROOT.ML, ZF/ex/Integ.thy: updated for EquivClass
     1 (*  Title: 	ZF/ex/llist-fn.thy
     2     ID:         $Id$
     3     Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
     4     Copyright   1993  University of Cambridge
     5 
     6 Functions for Lazy Lists in Zermelo-Fraenkel Set Theory 
     7 
     8 STILL NEEDS:
     9 co_recursion for defining lconst, flip, etc.
    10 a typing rule for it, based on some notion of "productivity..."
    11 *)
    12 
    13 LListFn = LList + LList_Eq +
    14 consts
    15   lconst   :: "i => i"
    16   flip     :: "i => i"
    17 
    18 rules
    19   lconst_def  "lconst(a) == lfp(univ(a), %l. LCons(a,l))"
    20 
    21   flip_LNil   "flip(LNil) = LNil"
    22 
    23   flip_LCons  "[| x:bool; l: llist(bool) |] ==> \
    24 \              flip(LCons(x,l)) = LCons(not(x), flip(l))"
    25 
    26 end