%  WORKING WITH TUPLES POSSIBILITY TESTING

eqq(x, (0, 0)).
eqq(y, (1, 1)).
iszerosum(X, Y) :- X1 == Y1, X2 == Y2, eqq(X, (X1, X2)), eqq(Y, (Y1, Y2)).

%plus(X, Y) :- eq(X, (ax, ay)), eq(Y, (bx, by)), ax + ay + bx + by.