two football players tackle another football player.
Nobody is tackling.
Two football players means two people versus nobody equals zero individuals.
exists e1 x1 x2 x3 x4 x5.(Theme(e1,x4) & Actor(e1,x1) & v_tackle(e1) & n_player(x4) & of(x4,x5) & n_football(x5) & -(x4 = x1) & n_player(x1) & n_player(x1) & of(x1,x3) & n_football(x3) & of(x1,x2) & n_football(x2) & card_eq_2(x1))
-exists e1 x1.(Actor(e1,x1) & v_tackle(e1) & n_person(x1))