src/HOL/Sexp.thy
changeset 923 ff1574a81019
child 972 e61b058d58d2
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/HOL/Sexp.thy	Fri Mar 03 12:02:25 1995 +0100
     1.3 @@ -0,0 +1,40 @@
     1.4 +(*  Title: 	HOL/Sexp
     1.5 +    ID:         $Id$
     1.6 +    Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory
     1.7 +    Copyright   1992  University of Cambridge
     1.8 +
     1.9 +S-expressions, general binary trees for defining recursive data structures
    1.10 +*)
    1.11 +
    1.12 +Sexp = Univ +
    1.13 +consts
    1.14 +  sexp      :: "'a item set"
    1.15 +
    1.16 +  sexp_case :: "['a=>'b, nat=>'b, ['a item, 'a item]=>'b, \
    1.17 +\                'a item] => 'b"
    1.18 +
    1.19 +  sexp_rec  :: "['a item, 'a=>'b, nat=>'b, 	\
    1.20 +\                ['a item, 'a item, 'b, 'b]=>'b] => 'b"
    1.21 +  
    1.22 +  pred_sexp :: "('a item * 'a item)set"
    1.23 +
    1.24 +inductive "sexp"
    1.25 +  intrs
    1.26 +    LeafI  "Leaf(a): sexp"
    1.27 +    NumbI  "Numb(a): sexp"
    1.28 +    SconsI "[| M: sexp;  N: sexp |] ==> M$N : sexp"
    1.29 +
    1.30 +defs
    1.31 +
    1.32 +  sexp_case_def	
    1.33 +   "sexp_case c d e M == @ z. (? x.   M=Leaf(x) & z=c(x))  \
    1.34 +\                           | (? k.   M=Numb(k) & z=d(k))  \
    1.35 +\                           | (? N1 N2. M = N1 $ N2  & z=e N1 N2)"
    1.36 +
    1.37 +  pred_sexp_def
    1.38 +     "pred_sexp == UN M: sexp. UN N: sexp. {<M, M$N>, <N, M$N>}"
    1.39 +
    1.40 +  sexp_rec_def
    1.41 +   "sexp_rec M c d e == wfrec pred_sexp M  \
    1.42 +\             (%M g. sexp_case c d (%N1 N2. e N1 N2 (g N1) (g N2)) M)"
    1.43 +end