--- a/Subst/UTerm.thy Tue Oct 24 14:59:17 1995 +0100
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,65 +0,0 @@
-(* Title: Substitutions/UTerm.thy
- Author: Martin Coen, Cambridge University Computer Laboratory
- Copyright 1993 University of Cambridge
-
-Simple term structure for unifiation.
-Binary trees with leaves that are constants or variables.
-*)
-
-UTerm = Sexp +
-
-types uterm 1
-
-arities
- uterm :: (term)term
-
-consts
- uterm :: "'a item set => 'a item set"
- Rep_uterm :: "'a uterm => 'a item"
- Abs_uterm :: "'a item => 'a uterm"
- VAR :: "'a item => 'a item"
- CONST :: "'a item => 'a item"
- COMB :: "['a item, 'a item] => 'a item"
- Var :: "'a => 'a uterm"
- Const :: "'a => 'a uterm"
- Comb :: "['a uterm, 'a uterm] => 'a uterm"
- UTerm_rec :: "['a item, 'a item => 'b, 'a item => 'b,
- ['a item , 'a item, 'b, 'b]=>'b] => 'b"
- uterm_rec :: "['a uterm, 'a => 'b, 'a => 'b,
- ['a uterm, 'a uterm,'b,'b]=>'b] => 'b"
-
-defs
- (*defining the concrete constructors*)
- VAR_def "VAR(v) == In0(v)"
- CONST_def "CONST(v) == In1(In0(v))"
- COMB_def "COMB(t,u) == In1(In1(t $ u))"
-
-inductive "uterm(A)"
- intrs
- VAR_I "v:A ==> VAR(v) : uterm(A)"
- CONST_I "c:A ==> CONST(c) : uterm(A)"
- COMB_I "[| M:uterm(A); N:uterm(A) |] ==> COMB(M,N) : uterm(A)"
-
-rules
- (*faking a type definition...*)
- Rep_uterm "Rep_uterm(xs): uterm(range(Leaf))"
- Rep_uterm_inverse "Abs_uterm(Rep_uterm(xs)) = xs"
- Abs_uterm_inverse "M: uterm(range(Leaf)) ==> Rep_uterm(Abs_uterm(M)) = M"
-
-defs
- (*defining the abstract constructors*)
- Var_def "Var(v) == Abs_uterm(VAR(Leaf(v)))"
- Const_def "Const(c) == Abs_uterm(CONST(Leaf(c)))"
- Comb_def "Comb(t,u) == Abs_uterm(COMB(Rep_uterm(t),Rep_uterm(u)))"
-
- (*uterm recursion*)
- UTerm_rec_def
- "UTerm_rec(M,b,c,d) == wfrec(trancl(pred_sexp), M,
- Case(%x g.b(x), Case(%y g. c(y), Split(%x y g. d(x,y,g(x),g(y))))))"
-
- uterm_rec_def
- "uterm_rec(t,b,c,d) ==
- UTerm_rec(Rep_uterm(t), %x.b(Inv(Leaf,x)), %x.c(Inv(Leaf,x)),
- %x y q r.d(Abs_uterm(x),Abs_uterm(y),q,r))"
-
-end