(* Title: ZF/Coind/Language.thy
ID: $Id$
Author: Jacob Frost, Cambridge University Computer Laboratory
Copyright 1995 University of Cambridge
*)
Language ="Datatype" + QUniv +
(* Abstract type of constants *)
consts
Const :: "i"
rules
constU "c:Const ==> c:univ(A)"
constNEE "c:Const ==> c ~= 0"
(* A function that captures how constant functions are applied to
constants *)
consts
c_app :: "[i,i] => i"
rules
c_appI "[| c1:Const; c2:Const |] ==> c_app(c1,c2):Const"
(* Abstract type of variables *)
consts
ExVar :: "i"
rules
exvarU "x:ExVar ==> x:univ(A)"
(* Datatype of expressions *)
consts
Exp :: "i"
datatype
"Exp" =
e_const("c:Const") |
e_var("x:ExVar") |
e_fn("x:ExVar","e:Exp") |
e_fix("x1:ExVar","x2:ExVar","e:Exp") |
e_app("e1:Exp","e2:Exp")
type_intrs "[constU,exvarU]"
end