/* father example */

bias(rule(father(X,Y),_Body),[X,Y,Z],
	[parent(X,Y),parent(Y,X),parent(X,Z),parent(Y,Z),male(X),male(Y),male(Z),
	female(X),female(Y),female(Z)]).

abducibles([male(_),female(_)]).

ic([]).

eplus([father(john,mary),father(david,steve)]).

eminus([father(katy,ellen),father(john,steve),father(steve,john),father(steve,katy)]). 


:-dynamic parent/2, male/1, female/1.


parent(john,mary).
male(john).

parent(david,steve).

parent(katy,ellen).
female(katy).