A young boy throwing a ball.
A young boy wearing a mitt is throwing a ball
It doesn't specify if the boy is wearing a mitt while throwing the ball.
exists e1 s1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_throw(e1) & n_ball(x3) & (x1 = x2) & n_boy(x1) & a_young(s1) & Theme(s1,x1))
exists e1 e2 s1 x1 x2 x3 x4.(Theme(e2,x4) & Actor(e2,x1) & v_throw(e2) & n_ball(x4) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_mitt(x3) & (x1 = x2) & n_boy(x1) & a_young(s1) & Theme(s1,x1))