Family domain experiment 2: results.
MPL
1. female_ancestor(X,Y) :- mother(X,Y).
2. male_ancestor(X,Y) :- father(X,Y).
3. female_ancestor(X,Y) :- mother(X,Z), female_ancestor(Z,Y).
4. male_ancestor(X,Y) :- father(X,Z), female_ancestor(Z,Y).
5. male_ancestor(X,Y) :- father(X,Z), male_ancestor(Z,Y).
6. female_ancestor(X,Y) :- female_ancestor(X,Z), male_ancestor(Z,Y).
ATRE
1. male_ancestor(X1,X2) :- father(X1,X2).
2. female_ancestor(X1,X2) :- mother(X1,X2).
3. male_ancestor(X1,X2) :- female_ancestor(X3,X2), male_ancestor(X1,X3).
4. male_ancestor(X1,X2) :- male_ancestor(X1,X3), male_ancestor(X3,X2).
5. female_ancestor(X1,X2) :- female_ancestor(X1,X3), female_ancestor(X3,X2).
6. female_ancestor(X1,X2) :- male_ancestor(X3,X2), female_ancestor(X1,X3).