woman(dorina).
woman(maria).
woman(ana).
man(marius).
man(mihai).
man(george).
man(andrei).
parent(maria,ana).
parent(maria,andrei).
parent(george,ana).
parent(george,andrei).
parent(marius,maria).
parent(dorina,maria).
parent(mihai,george).
mother(X,Y):-woman(X), parent(X,Y).
father(X,Y):-man(X), parent(X,Y).
sibling(X,Y):-parent(Z,X), parent(Z,Y), X\=Y.
brother(X,Y):-sibling(X,Y), man(X).
uncle(X,Y):-brother(X,Z), parent(Z,Y).
grandmother(X,Y):-mother(X,Z), parent(Z,Y).
grandfather(X,Y):-father(X,Z), parent(Z,Y).
ancestor(X,Y):-parent(X,Y).
ancestor(X,Y):-parent(Z,Y), ancestor(X,Z).