The boy is playing basketball.
Jill is walking.
Jill is a female name, not that of a boy.  The same person cannot be walking and playing basketball at the same time.
exists e1 x1 x2.(n_boy(x1) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_basketball(x2))
exists e1 x1.(ne_per_jill(x1) & Actor(e1,x1) & v_walk(e1))