src/CCL/Wfd.thy
 author wenzelm Sat, 17 Sep 2005 17:35:26 +0200 changeset 17456 bcf7544875b2 parent 3837 d7f033c74b38 child 20140 98acc6d0fab6 permissions -rw-r--r--
converted to Isar theory format;
```
(*  Title:      CCL/Wfd.thy
ID:         \$Id\$
Author:     Martin Coen, Cambridge University Computer Laboratory
*)

header {* Well-founded relations in CCL *}

theory Wfd
imports Trancl Type Hered
uses ("wfd.ML") ("genrec.ML") ("typecheck.ML") ("eval.ML")
begin

consts
(*** Predicates ***)
Wfd        ::       "[i set] => o"
(*** Relations ***)
wf         ::       "[i set] => i set"
wmap       ::       "[i=>i,i set] => i set"
"**"       ::       "[i set,i set] => i set"      (infixl 70)
NatPR      ::       "i set"
ListPR     ::       "i set => i set"

axioms

Wfd_def:
"Wfd(R) == ALL P.(ALL x.(ALL y.<y,x> : R --> y:P) --> x:P) --> (ALL a. a:P)"

wf_def:         "wf(R) == {x. x:R & Wfd(R)}"

wmap_def:       "wmap(f,R) == {p. EX x y. p=<x,y>  &  <f(x),f(y)> : R}"
lex_def:
"ra**rb == {p. EX a a' b b'. p = <<a,b>,<a',b'>> & (<a,a'> : ra | (a=a' & <b,b'> : rb))}"

NatPR_def:      "NatPR == {p. EX x:Nat. p=<x,succ(x)>}"
ListPR_def:     "ListPR(A) == {p. EX h:A. EX t:List(A). p=<t,h\$t>}"

ML {* use_legacy_bindings (the_context ()) *}

use "wfd.ML"
use "genrec.ML"
use "typecheck.ML"
use "eval.ML"

end
```