Prolog3

:- initialization(consult(kinship)).

rec :- consult(prog).

pred(X,Y) :-
    parent(X,Y);
    parent(X,Z), pred(Z,Y).

brother(X,Y) :-
    male(X),
    male(Y),
    parent(M,X),
    female(M),
    parent(F,X),
    male(F),
    parent(M,Y),
    parent(F,Y),
    X \= Y.

married0(X,Y) :-
    parent(X,Z),
    parent(Y,Z),
    X \= Y.

married(X,Y) :-
    setof(Y,married0(X,Y),Lst),
    member(Y,Lst).

husband(X,Y) :-
    married(X,Y),
    male(X).

cousin0(X,Y) :-
    parent(XP,X),
    parent(YP,Y),
    parent(Z,XP),
    parent(Z,YP),
    XP \= YP,
    \+ married(XP,YP),
    X \= Y.

cousin(X,Y) :-
    setof(Y,cousin0(X,Y),Lst),
    member(Y,Lst).

num_of_children(X,N) :-
    setof(Y,parent(X,Y),Lst),
    length(Lst,N).

nephews0(X,Y) :-
    parent(Z,Y),
    parent(Z,YY),
    parent(YY,X),
    Y \= YY.

nephews(X,Y) :-
    setof(Z,nephews0(Z,Y),NS),
    sort(NS,X).

common_child(X,Y,Z) :-
    parent(X,Z),
    parent(Y,Z).

family([F,M|C]) :-
    married(F,M),
    male(F),
    setof(CC,common_child(F,M,CC),CCC),
    sort(CCC,C).