Little boys play soccer on the field.
The children are using a ball.
Little boys are children.   When you play soccer you are using a ball.
exists e1 s1 x1 x2 x3.(n_field(x3) & on(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_play(e1) & n_soccer(x2) & n_boy(x1) & a_little(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_child(x1) & Theme(e1,x2) & Actor(e1,x1) & v_use(e1) & n_ball(x2))