The cowboy is falling off a bucking bull.
A man watching a bull sleep.
One cannot be falling off a bull and be watching a bull sleep simultaneously.
exists e1 s1 x1 x2 x3.(n_cowboy(x1) & a_off(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_fall(e1) & n_bull(x2) & of(x2,x3) & n_bucking(x3))
exists e1 x1 x2 x3 x4.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_watch(e1) & n_sleep(x3) & of(x3,x4) & n_bull(x4) & (x1 = x2) & n_man(x1))