parent(namihei,sazae).
parent(namihei,katsuo).
parent(namihei,wakame).
parent(fune,sazae).
parent(fune,katsuo).
parent(fune,wakame).
parent(sazae,tarao).
parent(masuo,tarao).

male(namihei).
male(katsuo).
male(masuo).
male(tarao).
female(wakame).
female(sazae).
female(fune).

daughter(D,P) :- parent(P,D), female(D).
son(S,P) :- parent(P,S), male(S).
father(F,C) :- parent(F,C), male(F).
mother(M,C) :- parent(M,C), female(M).

sister(X,Y) :- daughter(X,F), daughter(Y,F), \==(X,Y).
brother(X,Y) :- son(X,F), son(Y,F), \==(X,Y).

% Aの孫を表示
grandchild1(A,X) :- parent(A,X),parent(X,C).
grandchild2(A,X) :- parent(A,B),parent(B,X).