family.pl
family.pl
—
text/x-perl,
1 KB
File contents
parent(pam,bob). parent(tom,bob). parent(tom,liz). parent(bob,ann). parent(bob,pat). parent(pat,jim). male(bob). male(tom). male(jim). female(pam). female(liz). female(pat). female(ann). grandparent(X,Y) :- parent(X,Z), parent(Z,Y). father(X,Y) :- parent(X,Y), male(X). greatgrandfather(X,Y) :- father(X,Z), grandparent(Z,Y). person(X) :- male(X). person(X) :- female(X). ancestor(X,X) :- person(X). ancestor(X,Y) :- parent(X,Z), ancestor(Z,Y).