A boy is leading donkeys on a path.
The boy is not behind the donkeys.
Because the boy is leading the donkeys, it implies that he is in front of them, not behind them.
exists e1 x1 x2 x3.(on(e1,x3) & n_path(x3) & Theme(e1,x2) & Actor(e1,x1) & v_lead(e1) & n_donkey(x2) & n_boy(x1))
exists x1 x2.(n_donkey(x2) & n_boy(x1) & -exists p1.behind(x1,x2))