A little boy sits on a rock and plays with leaves.
The boy has no leaves.
The boy can either have leaves or not have leaves.
exists e2 e1 s1 s2 x1 x2 x3 x4.(with(e2,x4) & n_leaf(x4) & Actor(e2,x3) & v_play(e2) & n_boy(x3) & a_little(s2) & Theme(s2,x3) & on(e1,x2) & n_rock(x2) & Actor(e1,x1) & v_sit(e1) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists x1.(n_boy(x1) & -exists e1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_have(e1) & n_leaf(x2)))