A boy pets a sleeping tiger.
A boy is in a tiger's pen.
A boy is in a tiger's pen doesn't mean that the tiger is the boy's pet.
exists e2 e1 x1 x2.(Theme(e2,x2) & Actor(e2,x1) & v_pet(e2) & n_tiger(x2) & Actor(e1,x2) & v_sleep(e1) & n_boy(x1))
exists p1 x1.(exists x2 x3.(in(x1,x3) & n_pen(x3) & of(x3,x2) & n_tiger(x2)) & n_boy(x1))