%% Copyright (c) 1991,1994,1995 by Carnegie Mellon University %%
%% Copyright (c) 1994,1995 by AT&T Bell Laboratories          %%
%% Copyright (c) 1995,1996 by the University of Pennsylvania		%%

%% For information about the distributaion, copying, and modification	%%
%% of this software, please read the file COPYING located in the root	%%
%% directory of this distribnutaion. If you did not receive the file	%%
%% COPYING write to Philip Wickline at the address below.		%%

%% This program is distributed in the hope that it will be useful but	%%
%% WITHOUT ANY WARRANTY; without even the implied warranty of		%%
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the file	%%
%% COPYING for more details.						%%

%% For information about the structure of the Terzo lambdaProlog	%%
%% implementation, see the file src/README in this distribution. Please	%%
%% address any questions about this code or the Terzo lambdaProlog	%%
%% implementation to Philip Wickline at <philipw@saul.cis.upenn.edu>.	%%

%% Authors: Amy Felty <felty@research.att.com>                %%
%%          Frank Pfenning <fp@cs.cmu.edu>                    %%
%%          Philip Wickline <philipw@saul.cis.upenn.edu>      %%

module System.
accumulate	Logicals, Exception, StreamIo, File,
		Magic, Eval, List, Control, Trace.

	type	'='	A -> A -> o.
	infix	'='	4.
	X = X.

	% Universal printing
	type	print		string -> o.
	print X	:- output std_out X.

	% Universal reading
	type	read		A -> o.
	read Y :- input_line std_in X, string_to_term X Y.

	type	solve		o -> o.
	solve G :- G.

	type	not	        o -> o.
	% not G
	%	Fails if G succeeds, and succeeds otherwise.
	not G :- solve G, !, fail.	% ``solve G'' instead of G is critical!
	not G.