test

DOMAINS
cell=c(integer,integer)
list=cell*
int_list=integer*
PREDICATES
solution(list)
member(integer,int_list)
nonattack(cell,list)
CLAUSES
solution([]).
solution([c(X,Y)|Others]):-
solution(Others),
member(Y,[1,2,3,4,5,6,7,8]),
nonattack(c(X,Y),Others).
nonattack(_,[]).
nonattack(c(X,Y),[c(X1,Y1)|Others]):-
Y<>Y1,
Y1-Y<>X1-X,
Y1-Y<>X-X1,
nonattack(c(X,Y),Others).
member(X,[X|_]).
member(X,[_|Z]):-
member(X,Z).
GOAL
solution([c(1,1),c(2,B),c(3,C),c(4,8),c(5,E),c(6,F),c(7,G),c(8,H)]).