%   File   : crossbar.pl
%   Author : Neng-Fa ZHOU
%   Date   : 1994

top:-
    cross(List),
    write(List),nl.
    
go:-
    statistics(runtime,[Start|_]),
    top,
    statistics(runtime,[End|_]),
    T is End-Start,
    write('%execution time ='), write(T), write(' milliseconds'),nl.

cross(List):-
	List=[V1,V2,V3,V4,V5,V6,V7,V8,V9,V10,
	      V11,V12,V13,V14,V15,V16,V17,V18,V19,V20],
       List in 0..20,
        V1 in [2,4,6,7,8,9,10,11,16,18,20],
	V2 in [2,3,4,8,10,12,17,19,20],
	V3 in [2,3,4,6,8,9,11,17,18],
	V4 in [1,3,4,5,6,7,9,10,11,13,18],
	V5 in [1,5,6,10,12,13,14,17,18,19,20],
	V6 in [1,3,10,12,15,16,19,20],
	V7 in [5,8,9,10,17],
        V8 in [1,2,5,6,7,12,14,15,16,17],
	V9 in [1,2,3,4,5,7,11,12,13,14,16,17,20],
	V10 in [4,5,8,9,10,11,13,17,18,19,20],
	V11 in [2,4,6,7,8,10,12,14,17,18,20],
	V12 in [3,7,8,9,10,13,14,15,18,20],
	V13 in [2,3,6,7,8,9,11,13,16,20],
	V14 in [2,3,5,6,8,9,12,13,15,16,17,18],
	V15 in [2,7,8,10,12,13,14,15,16,17,18,20],
	V16 in [1,2,6,11,13,16,17,19,20],
	V17 in [1,3,6,9,13,19],
	V18 in [1,3,6,7,8,10,13,14,19],
        V19 in [1,2,3,4,5,6,7,9,11,12,14,16,17,19,20],
        V20 in [3,5,6,7,8,9,11,12,13,14,16,18,20],
	alldifferent(List),
    labeling(List).