Subst/AList.thy
author lcp
Fri, 14 Apr 1995 11:23:33 +0200
changeset 248 c3913a79b6ae
parent 194 b93cc55cb7ab
permissions -rw-r--r--
Simplified some proofs and made them work for new hyp_subst_tac.

(*  Title: 	Substitutions/alist.thy
    Author: 	Martin Coen, Cambridge University Computer Laboratory
    Copyright   1993  University of Cambridge

Association lists.
*)

AList = List + 

consts

  alist_rec  :: "[('a*'b)list, 'c, ['a, 'b, ('a*'b)list, 'c]=>'c] => 'c"
  assoc      :: "['a,'b,('a*'b) list] => 'b"

rules

  alist_rec_def "alist_rec(al,b,c) == list_rec(b, split(c), al)"

  assoc_def     "assoc(v,d,al) == alist_rec(al,d,%x y xs g.if(v=x,y,g))"

end