male(Peter).
male(Stewie).
male(Chris).
male(Francis).
male(Joe).
male(Kevin).

female(Louis).
female(Meg).
female(Thelma).
female(Bonnie).
female(Susie).


father(Peter,Stewie).
father(Peter,Chris).
father(Peter,Meg).
father(Joe,Kevin).
father(Joe,Susie).
father(Francis,Peter).
father(Francis,Joe).

mother(Louis,Stewie).
mother(Louis,Chris).
mother(Louis,Meg).
mother(Thelma,Peter).
mother(Bonnie,Kevin).
mother(Bonnie,Susie).


brother(X,Y) :- mother(Z,X),
        mother(Z,Y),
 male(X),
 X \= Y.

sister(X,Y) :- mother(Z,X),
       mother(Z,Y),
       female(X),
       X \= Y.

grandfather(X,Y) :- father(Z,Y); mother(Z,Y),
     father(X,Z),
     male(X).

grandmother(X,Y) :- father(Z,Y); mother(Z,Y),
     mother(X,Z),
     female(X).

uncle(X,Y) :- brother(X,Z),
      father(Z,Y); mother(Z,Y),
      male(X).

aunt(X,Y) :- sister(X,Z),
     father(Z,Y); mother(Z,Y),
     female(X).

cousin(X,Y) :- father(Z,X); mother(Z,X),
       father(Q,Y); mother(Q,Y),
       brother(Z,Q); sister(Z,Q).

nephew(X,Y) :- father(Z,X); mother(Z,X),
       brother(X,Y); sister(X,Y).

related(X,Y) :- uncle(X,Y); uncle(Y,X);
               aunt(X,Y); aunt(Y,X);
 brother(X,Y); brother(Y,X);
 sister(X,Y); sister(Y,X);
               cousin(X,Y); cousin(Y,X);
 nephew(X,Y); nephew(Y,X);
 mother(X,Y); mother(Y,X);
 father(X,Y); father(Y,X);
 grandmother(X,Y); grandmother(Y,X);
 grandfather(X,Y); grandfather(Y,X).