parent(maria,anna).
parent(petr,anna).
parent(maria,stepa).
parent(petr,stepa).
parent(matilda,petr).
parent(matilda,sonya).
parent(sonya,tony).

man(petr).
man(stepa).
man(tony).

woman(sonya).
woman(matilda).
woman(anna).
woman(maria).

married(petr,maria).

sister(X,Y):-woman(X),parent(Z,Y),parent(Z,X),X\=Y.
grandma(X,Y):-woman(X),parent(X,Z),parent(Z,Y).
grandd(X,Y):-woman(X),parent(Z,X),parent(Y,Z).
cusin(X,Y):-man(X),parent(P,X),parent(S,Y),parent(R,P),parent(R,S),X\=Y.

aunt(X,Y):-woman(X),parent(Z,Y),sister(X,Z).
niece(X,Y):-woman(X),parent(Par1,X),parent(Par2,Y),parent(Par2,Par1),Par1\=Y.
mother_in_law(X,Y):-woman(X),parent(X,Z),(married(Y,Z);married(Z,Y)).
daughter_in_law(X,Y):-woman(X),parent(Y,Son),married(Son,X).
daughter_in_law(X,Y):-woman(X),parent(Y,Son),married(X,Son).