1		/* -*- Mode:Prolog; coding:ISO-8859-1; -*- */
2		:- module(csp_basic,[safe_less_than/2, safe_less_than_equal/2,
3		safe_less_than/3, safe_less_than_equal/3,
4		enumerate_csp_int/3]).
5
6		:- use_module(probsrc(module_information)).
7		:- module_info(group,csp).
8		:- module_info(description,'Basic operations on CSP values.').
9
10		:- use_module(probsrc(self_check)).
11		:- assert_must_succeed( (csp_basic:safe_less_than(X,Y), X=1,Y=2)).
12		:- assert_must_fail( (csp_basic:safe_less_than(X,Y), X=1,Y=1)).
13		:- assert_must_fail( (csp_basic:safe_less_than(X,Y), X=2,Y=1)).
14
15		:- block safe_less_than(-,?),safe_less_than(?,-).
16		safe_less_than(X,Y) :- X<Y.
17
18		:- assert_must_succeed( (csp_basic:safe_less_than(X,Y,R), X=1,Y=2,R==true)).
19		:- assert_must_succeed( (csp_basic:safe_less_than(X,Y,R), X=2,Y=2,R==false)).
20		:- block safe_less_than(-,?,?),safe_less_than(?,-,?).
21		safe_less_than(X,Y,R) :- (X<Y -> R=true ; R=false).
22
23		:- assert_must_succeed( (csp_basic:safe_less_than_equal(X,Y), X=1,Y=2)).
24		:- assert_must_succeed( (csp_basic:safe_less_than_equal(X,Y), X=1,Y=1)).
25		:- assert_must_fail( (csp_basic:safe_less_than_equal(X,Y), X=2,Y=1)).
26		:- block safe_less_than_equal(-,?),safe_less_than_equal(?,-).
27		safe_less_than_equal(X,Y) :- X=<Y.
28
29		:- assert_must_succeed( (csp_basic:safe_less_than_equal(X,Y,R), X=1,Y=2,R==true)).
30		:- assert_must_succeed( (csp_basic:safe_less_than_equal(X,Y,R), X=2,Y=2,R==true)).
31		:- assert_must_succeed( (csp_basic:safe_less_than_equal(X,Y,R), X=2,Y=1,R==false)).
32		:- block safe_less_than_equal(-,?,?),safe_less_than_equal(?,-,?).
33		safe_less_than_equal(X,Y,R) :- (X=<Y -> R=true ; R=false).
34
35		:- assert_must_succeed( (csp_basic:enumerate_csp_int(X,1,10), X==5)).
36		enumerate_csp_int(N,X,Y) :- X=<Y,
37	?	(N=X ; X1 is X+1, enumerate_csp_int(N,X1,Y)).