branch(dave, b).
branch(eve, b).
branch(frank, c).
branch(grace, c).
branch(heidi, b).
branch(ivan, b).
branch(judy, c).
generation(bob, 1).
generation(carol, 1).
generation(dave, 2).
generation(eve, 2).
generation(frank, 2).
generation(grace, 2).
generation(heidi, 3).
generation(ivan, 3).
generation(judy, 3).
cousin(dave, frank).
cousin(dave, grace).
cousin(eve, frank).
cousin(eve, grace).
cousin(frank, dave).
cousin(frank, eve).
cousin(grace, dave).
cousin(grace, eve).
cousin(heidi, judy).
cousin(ivan, judy).
cousin(judy, heidi).
cousin(judy, ivan).