I need a code in prolog.
Assume we defined some persons in family tree.
How can I write a function that get two persons name and process if they have same generation and who is their same ancestor?
parent(chester,irvin).
parent(chester,clarence).
parent(chester,mildred).
parent(irvin,ron).
parent(irvin,ken).
parent(clarence,shirley).
parent(clarence,sharon).
parent(clarence,charlie).
parent(mildred,mary).
male(chester).
female(mildred).
male(irvin).
female(shirley).
male(clarence).
female(sharon).
male(ron).
female(mary).
male(ken).
male(charlie).
father(X,Y) :- parent(X,Y), male(X).
mother(X,Y) :- parent(X,Y), female(X).
grandparent(X,Y) :- parent(X,Z), parent(Z,Y).
paternalgrandfather(X,Y) :- father(X,Z), father(Z,Y).
sibling(X,Y) :- parent(Z,X), parent(Z,Y).
brothers(X,Y) :- sibling(X,Y),male(X),male(Y), \+ (X=Y).
samegeneration(x,y) :- HERE I DONT KNOW WHAT TO DO