(* ID: $Id$
Author: Claire Quigley
Copyright 2004 University of Cambridge
*)
val gcounter = ref 0;
fun USYN_ERR func mesg = Utils.ERR {module = "USyntax", func = func, mesg = mesg};
fun dest_neg(Const("Not",_) $ M) = M
| dest_neg _ = raise USYN_ERR "dest_neg" "not a negation";
fun iscomb a = if is_Free a then
false
else if is_Var a then
false
else if USyntax.is_conj a then
false
else if USyntax.is_disj a then
false
else if USyntax.is_forall a then
false
else if USyntax.is_exists a then
false
else
true;
fun getstring (Var (v,T)) = fst v
|getstring (Free (v,T))= v;
fun twoisvar (a,b) = is_Var b;
fun twoisfree (a,b) = is_Free b;
fun twoiscomb (a,b) = iscomb b;
fun strequalfirst a (b,c) = (getstring a) = (getstring b);
fun fstequal a b = a = fst b;
fun takeout (i,[]) = []
| takeout (i,(x::xs)) = if (i>0) then
(x::(takeout(i-1,xs)))
else
[];
(* Presumably here, we would allow is_Var f for doing HOL, i.e. can subst for propositions *)
fun is_Abs (Abs _) = true
| is_Abs _ = false;
fun is_Bound (Bound _) = true
| is_Bound _ = false;
fun is_hol_tm t =
if (is_Free t) then
true
else if (is_Var t) then
true
else if (is_Const t) then
true
else if (is_Abs t) then
true
else if (is_Bound t) then
true
else
let val (f, args) = strip_comb t in
if ((is_Free f) orelse (is_Var f)) andalso (forall is_hol_tm args) then
true (* should be is_const *)
else
false
end;
fun is_hol_fm f = if USyntax.is_neg f then
let val newf = USyntax.dest_neg f in
is_hol_fm newf
end
else if USyntax.is_disj f then
let val {disj1,disj2} = USyntax.dest_disj f in
(is_hol_fm disj1) andalso (is_hol_fm disj2) (* shouldn't this be and ? *)
end
else if USyntax.is_conj f then
let val {conj1,conj2} = USyntax.dest_conj f in
(is_hol_fm conj1) andalso (is_hol_fm conj2)
end
else if (USyntax.is_forall f) then
let val {Body, Bvar} = USyntax.dest_forall f in
is_hol_fm Body
end
else if (USyntax.is_exists f) then
let val {Body, Bvar} = USyntax.dest_exists f in
is_hol_fm Body
end
else if (iscomb f) then
let val (P, args) = strip_comb f in
((is_hol_tm P)) andalso (forall is_hol_fm args)
end
else
is_hol_tm f; (* should be is_const, nee
d to check args *)
fun hol_literal t =
(is_hol_fm t) andalso
( not ((USyntax.is_conj t) orelse (USyntax.is_disj t) orelse (USyntax.is_forall t) orelse (USyntax.is_exists t)));
(*PROBLEM HERE WITH THINGS THAT HAVE TWO RANDS e.g. P x y *)
fun getcombvar a = let val {Rand = rand, Rator = rator} = USyntax.dest_comb a in
if (iscomb rand) then
getcombvar rand
else
rand
end;
fun free2var v = let val thing = dest_Free v
val (name,vtype) = thing
val index = (name,0) in
Var (index,vtype)
end;
fun var2free v = let val (index, tv) = dest_Var v
val istr = fst index in
Free (istr,tv)
end;
fun is_empty_seq thisseq = case Seq.chop (1, thisseq) of
([],_) => true
| _ => false
fun getnewenv thisseq =
let val seqlist = Seq.list_of thisseq
val envpair =hd seqlist in
fst envpair
end;
fun getnewsubsts thisseq = let val seqlist = Seq.list_of thisseq
val envpair =hd seqlist in
snd envpair
end;
fun prover s = prove_goal HOL.thy s (fn _ => [blast_tac HOL_cs 1]);
fun int_of_string str = valOf (Int.fromString str)
handle Option => error ("int_of_string: " ^ str);
exception ASSERTION of string;