female(lola). female(bonnie). female(bonnie_h). female(carrie). female(phyl). female(rachel). male(dave). male(tom). male(theo). male(dennis). male(bill). male(tom_h). parent(bill, tom). parent(phyl, tom). parent(tom, bonnie). parent(tom, theo). parent(tom, rachel). parent(lola, bonnie). parent(lola, theo). parent(lola, rachel). parent(carrie, adam). parent(dennis, adam). parent(bonnie_h, lola). parent(bonnie_h, carrie). parent(tom_h, lola). parent(tom_h, carrie). parent(phyl, dave). husband(tom, lola). husband(dennis, carrie). husband(bill, phyl). husband(tom_h, bonnie_h). wife(X,Y) :- husband(Y,X). spouse(X,Y) :- husband(X,Y). spouse(X,Y) :- wife(X,Y). mother(X,Y) :- female(X), parent(X,Y). father(X,Y) :- male(X), parent(X,Y). sibling(X,Y) :- mother(Z,X), mother(Z,Y), X \== Y. brother(X,Y) :- male(X), sibling(X,Y). sister(X,Y) :- female(X), sibling(X,Y). brother_in_law(X,Y) :- brother(X, Z), spouse(Z, Y). brother_in_law(X,Y) :- husband(X, Z), sister(Z, Y). sister_in_law(X,Y) :- sister(X, Z), spouse(Z, Y). sister_in_law(X,Y) :- wife(X, Z), brother(Z, Y). ancestor(X,Y) :- parent(X,Y). ancestor(X,Y) :- parent(X,Z), ancestor(Z,Y).