family tree

% parent(X,Y) means that person X is a parent (father or mother) of person Y

parent(alex,julia).
parent(alex,rosa).
parent(robi,alex).
parent(robi,jon).
parent(lina,julia).
parent(lina,rosa).
parent(romeo,peter).
parent(julia,peter).
parent(rosa,silvia).
parent(oscar,ida).
parent(eva,ida).
parent(eva,bruno).
parent(peter,bruno).
parent(peter,georg).
parent(peter,irma).
parent(ruth,georg).
parent(ruth,irma).
parent(silvia,otto).
parent(silvia,pascal).
parent(irma,olga).
parent(irma,jean).
parent(otto,olga).
parent(otto,jean).
parent(jean,tina).
parent(marie,tina).


% male(X) means that X is a male person

male(alex).
male(romeo).
male(oscar).
male(peter).
male(bruno).
male(georg).
male(otto).
male(pascal).
male(jean).
male(jon).


% husband(X,Y) means that person X is the husband of person Y

husband(alex,lina).
husband(romeo,julia).
husband(oscar,eva).
husband(peter,ruth).
husband(otto,irma).
husband(jean,marie).


% female
female(X) :- \+ male(X).

% father
father(X,Y) :- parent(X,Y),male(X).

% mother
mother(X,Y) :- parent(X,Y),female(X).

% son
son(X,Y) :- male(X),parent(Y,X).

% daughter
daughter(X,Y) :- female(X),parent(Y,X).

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


% Brother
brother(X,Y) :-
    parent(Z, X),
    parent(Z, Y),
    X \= Y,
    male(X).


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



% wife
wife(X,Y) :-
    female(X),
    husband(Y,X).

%married
married(X,Y) :-
    husband(X,Y);
    wife(X,Y).

% grandchild
grandchild(X,Y) :-
    parent(Z, X),
    parent(Y, Z).



% grandparent
grandparent(X,Y) :-
    parent(X, Z),
    parent(Z, Y).


% grandfather
 grandfather(X,Y) :-
    male(X),
    parent(X, Z),
    parent(Z, Y).


% grandmother
grandmother(X,Y) :-
    female(X),
    parent(X, Z),
    parent(Z, Y).


% uncle
uncle(X,Y) :-
    male(X),
    parent(Z, Y),
    brother(X, Z).



% halfbrother
commonmother(X,Y):-
    mother(Z,X),
    mother(Z,Y).
commonfather(X,Y):-
    father(Z,X),
    father(Z,Y).

halfbrother(X,Y) :-
    male(X),
    commonmother(X,Y),
    \+commonfather(X, Y);
    male(X),
    commonfather(X,Y),
    \+commonmother(X, Y).






% halfsister
halfsister(X,Y) :-
    female(X),
    commonmother(X,Y),
    \+commonfather(X, Y);
    female(X),
    commonfather(X,Y),
    \+commonmother(X, Y).


% stepbrother
stepbrother(X,Y) :-
    male(X),
    father(Z,X),
    mother(W,Y),
    married(Z,W);
    male(X),
    mother(Z,X),
    father(W,Y),
    married(Z,W).


% stepsister
stepsister(X,Y) :-
    female(X),
    father(Z,X),
    mother(W,Y),
    married(Z,W);
    female(X),
    mother(Z,X),
    father(W,Y),
    married(Z,W).



% ancestor
ancestor(X,Y) :- parent(X,Y).
ancestor(X,Y) :- parent(X,Z),ancestor(Z,Y).


% descendant

descendant(X,Y) :- parent(Y,X).
descendant(X,Y) :- parent(Z,X),ancestor(Y,Z).



% Father-in-law
 fatherinlaw(X,Y) :-
    father(X,Z),
    husband(Z,Y);
    father(X,Z),
    wife(Z,Y).



% mother-in-law
motherinlaw(X,Y)  :-
    mother(X,Z),
    married(Z,Y).




% familycomn
familycommon(X,Y):-
    father(X,Y);
    mother(X,Y);
    sister(X,Y);
    brother(X,Y);
    son(X,Y);
    daughter(X,Y);
    sibling(X,Y);
    married(X,Y);
    grandchild(X,Y);
    grandparent(X,Y);
    grandfather(X,Y);
    grandmother(X,Y);
    uncle(X,Y) ;
    halfbrother(X,Y);
    halfsister(X,Y);
    stepbrother(X,Y);
    stepsister(X,Y);
    ancestor(X,Y) ;
    fatherinlaw(X,Y);
    motherinlaw(X,Y);
    motherinlaw(Z,X),
    motherinlaw(Z,Y);
    fatherinlaw(Z,X),
    fatherinlaw(Z,Y).