A pitcher stands on the mound.
The pitcher is a good player.
Not all pitchers are good players.
exists e1 x1 x2.(n_mound(x2) & on(e1,x2) & Actor(e1,x1) & v_stand(e1) & n_pitcher(x1))
exists p1 x1.(n_pitcher(x1) & exists s1 x2.((x1 = x2) & n_player(x2) & a_good(s1) & Theme(s1,x2)))