Trabalhos

% % Rules % is_right_of(L, R, [L | [R | _]]). is_right_of(L, R, [_ | Rest]) :- is_right_of(L, R, Rest). next_to(X, Y, List) :- is_right_of(X, Y, List). next_to(X, Y, List) :- is_right_of(Y, X, List). % % Facts % % house(Color, Nationality, Pet, Drink, Smoke). owns_zebra(Who, Street) :- Street = [_House1, _House2, _House3, _House4, _House5], member(house(red, englishman, _, _, _), Street), member(house(_, spaniard, dog, _, _), Street), member(house(green, _, _, coffee, _), Street), member(house(_, ukrainian, _, tea, _), Street), is_right_of(house(green, _, _, _, _), house(ivory, _, _, _, _), Street), member(house(_, _, snails, _, old_gold), Street), member(house(yellow, _, _, _, kools), Street), [_, _, house(_, _, _, milk, _), _, _] = Street, [house(_, norwegian, _, _, _) | _] = Street, next_to(house(_, _, _, _, chesterfields), house(_, _, fox, _, _), Street), next_to(house(_, _, _, _, kools), house(_, _, horse, _, _), Street), member(house(_, _, _, orange_juice, lucky_strike), Street), member(house(_, japanese, _, _, parliaments), Street), next_to(house(_, norwegian, _, _, _), house(blue, _, _, _, _), Street), member(house(_, Who, zebra, _, _), Street).

-------------------------------------------------------------------------------------------------------------------------

esquerda(X, Y, [X,Y|_]). esquerda(X, Y, [_|R]) :- esquerda(X, Y, R).

direita(X, Y, [Y,X|_]). direita(X, Y, [_|R]) :- direita(X, Y, R).