Football players engaged in a tackle.
The players are tackling
engaged in a tackle can be written as are tackling.
exists e1 e2 x1 x2 x3 x4.(Actor(e2,x1) & v_tackle(e2) & in(e1,x4) & n_a(x4) & Theme(e1,x3) & v_engage(e1) & (x1 = x3) & n_player(x1) & of(x1,x2) & n_football(x2))
exists e1 x1.(n_player(x1) & Actor(e1,x1) & v_tackle(e1))