A boy chasing a baseball.
The boy is sitting down.
If he is chasing a baseball, he is not sitting down.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_chase(e1) & n_baseball(x3) & (x1 = x2) & n_boy(x1))
exists e1 s1 x1.(n_boy(x1) & a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1))