function-package: Changed record usage to make sml/nj happy...
(* Title: HOL/Tools/function_package/lib.ML
ID: $Id$
Author: Alexander Krauss, TU Muenchen
A package for general recursive function definitions.
Some fairly general functions that should probably go somewhere else...
*)
fun mk_forall (var as Free (v,T)) t =
all T $ Abs (v,T, abstract_over (var,t))
| mk_forall _ _ = raise Match
(* Builds a quantification with a new name for the variable. *)
fun mk_forall_rename ((v,T),newname) t =
all T $ Abs (newname,T, abstract_over (Free (v,T),t))
(* Constructs a tupled abstraction from an arbitrarily nested tuple of variables and a term. *)
fun tupled_lambda vars t =
case vars of
(Free v) => lambda (Free v) t
| (Var v) => lambda (Var v) t
| (Const ("Pair", Type ("fun", [Ta, Type ("fun", [Tb, _])]))) $ us $ vs =>
(HOLogic.split_const (Ta,Tb, fastype_of t)) $ (tupled_lambda us (tupled_lambda vs t))
| _ => raise Match
fun dest_all (Const ("all", _) $ Abs (a as (_,T,_))) =
let
val (n, body) = Term.dest_abs a
in
(Free (n, T), body)
end
| dest_all _ = raise Match
(* Removes all quantifiers from a term, replacing bound variables by frees. *)
fun dest_all_all (t as (Const ("all",_) $ _)) =
let
val (v,b) = dest_all t
val (vs, b') = dest_all_all b
in
(v :: vs, b')
end
| dest_all_all t = ([],t)
(* unfold *)
fun unfold P f g b x = if (P x) then ((f x)::(unfold P f g b (g x))) else (b x)
val dest_implies_list =
split_last o (unfold Logic.is_implies (fst o Logic.dest_implies) (snd o Logic.dest_implies) single)
fun implies_elim_swp a b = implies_elim b a
fun map3 _ [] [] [] = []
| map3 f (x :: xs) (y :: ys) (z :: zs) = f x y z :: map3 f xs ys zs
| map3 _ _ _ _ = raise UnequalLengths;
(* forms all "unordered pairs": [1, 2, 3] ==> [(1, 1), (1, 2), (1, 3), (2, 2), (2, 3), (3, 3)] *)
fun upairs [] = []
| upairs (x::xs) = map (pair x) (x::xs) @ upairs xs