The scuba diver is underwater.
The diver is spearfishing.
The scuba diver is not implied to be spearfishing.
exists p1 x1 x2.(n_diver(x1) & of(x1,x2) & n_scuba(x2) & exists x3.((x1 = x3) & n_underwater(x3)))
exists e1 x1.(n_diver(x1) & Actor(e1,x1) & v_spearfish(e1))