Pigeons swarm all over a boy.
A boy is swarmed by toads.
Pigeons are not toads.
exists e1 x1 x2.(r_all(e1) & over(e1,x2) & n_boy(x2) & Actor(e1,x1) & v_swarm(e1) & n_pigeon(x1))
exists e1 x1 x2.(Actor(e1,x2) & n_toad(x2) & Theme(e1,x1) & v_swarm(e1) & n_boy(x1))