A scuba diver is playing the drums.
a scuba diver plays a drums
He is playing the drums, not a drum.
exists e1 x1 x2 x3.(n_drum(x3) & Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_diver(x1) & of(x1,x2) & n_scuba(x2))
exists e1 x1 x2 x3.(Theme(e1,x3) & Actor(e1,x1) & v_play(e1) & n_drum(x3) & n_diver(x1) & of(x1,x2) & n_scuba(x2))