A boy sitting on a stump.
a boy is sitting down.
A boy is sitting, so he must be sitting down
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_stump(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_boy(x1))
exists e1 s1 x1.(a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1) & n_boy(x1))