/*
The contents of this file are subject to the Mozilla Public License
Version 1.1 (the "License"); you may not use this file except in
compliance with the License. You may obtain a copy of the License at:
http://www.mozilla.org/MPL/
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the speciafic language governing
rights and limitations under the License.
The Original Code is the contents of this file.
The Initial Developer of the Original Code is SICS, Swedish
Institute of Computer Science AB (SICS).
Portions created by the Initial Developer are Copyright (C) 2007
of the Initial Developer. All Rights Reserved.
Contributor(s):
_____Mats Carlsson
_____Nicolas Beldiceanu
Alternatively, if the contents of this file is included as a part of
SICStus Prolog distribution by SICS, it may be used under the terms of
an appropriate SICStus Prolog License Agreement (the "SICStus Prolog
License"), in which case the provisions of the SICStus Prolog License
are applicable instead of those above.
*/
:- multifile
ctr_predefined/1,
ctr_date/2,
ctr_persons/2,
ctr_origin/3,
ctr_usual_name/2,
ctr_synonyms/2,
ctr_types/2,
ctr_arguments/2,
ctr_exchangeable/2,
ctr_restrictions/2,
ctr_typical/2,
ctr_pure_functional_dependency/2,
ctr_functional_dependency/3,
ctr_contractible/4,
ctr_extensible/4,
ctr_aggregate/3,
ctr_example/2,
ctr_draw_example/9,
ctr_cond_imply/5,
ctr_see_also/2,
ctr_key_words/2,
ctr_derived_collections/2,
ctr_graph/7,
ctr_graph/9,
ctr_eval/2,
ctr_sol/6,
ctr_logic/3,
ctr_application/2.
ctr_date(opposite_sign,['20100821']).
ctr_origin(opposite_sign, 'Arithmetic.', []).
ctr_arguments(opposite_sign,
['VAR1'-dvar,
'VAR2'-dvar]).
ctr_exchangeable(opposite_sign,
[args([['VAR1','VAR2']])]).
ctr_restrictions(opposite_sign, []).
ctr_typical(opposite_sign,
['VAR1' =\= 0]).
ctr_predefined(opposite_sign).
ctr_example(opposite_sign,
opposite_sign(6,-3)).
ctr_see_also(opposite_sign,
[link('implies (if swap arguments)', abs_value, '', []),
link('comparison swapped', same_sign, '', [])]).
ctr_key_words(opposite_sign,['predefined constraint',
'arithmetic constraint',
'binary constraint' ,
'arc-consistency' ]).
ctr_eval(opposite_sign, [checker(opposite_sign_c),
builtin(opposite_sign_b)]).
opposite_sign_c(VAR1, VAR2) :-
check_type(int, VAR1),
check_type(int, VAR2),
(VAR1 = 0 -> true ;
VAR2 = 0 -> true ;
VAR1 > 0 -> VAR2 < 0 ; VAR2 > 0).
opposite_sign_b(VAR1, VAR2) :-
check_type(dvar, VAR1),
check_type(dvar, VAR2),
(VAR1 #>= 0 #/\ VAR2 #=< 0) #\/ (VAR2 #>= 0 #/\ VAR1 #=< 0).