Boy playing on the grass with an orange ball.
The girl was playing with the ball.
The boy cannot be a girl at the same time.
exists x1 x2 x3 x4 x5.(n_grass(x3) & a_topic(x1) & with(x1,x4) & n_ball(x4) & of(x4,x5) & n_orange(x5) & on(x1,x3) & n_playing(x1) & (x1 = x2) & ne_nam_boy(x2))
exists e1 x1 x2.(n_ball(x2) & n_girl(x1) & with(e1,x2) & Actor(e1,x1) & v_play(e1))