People watch a musician play the guitar.
People are looking at a car wreck.
One cannot be looking at a car wreck and watching a musician play the guitar at the same time.
exists e1 s1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_watch(e1) & n_guitar(x3) & (x2 = x3) & n_play(x2) & a_musician(s1) & Theme(s1,x2) & n_people(x1))
exists e1 x1 x2 x3.(at(e1,x2) & n_wreck(x2) & of(x2,x3) & n_car(x3) & Actor(e1,x1) & v_look(e1) & n_people(x1))