A boy sits on the tall fence post and smiles.
The boy is smiling at his horses.
A boy sits on the tall fence post and smiles doesn't imply he smiles at his horses.
exists e2 e1 s1 x1 x2 x3 x4.(n_post(x2) & of(x2,x3) & n_fence(x3) & a_tall(s1) & Theme(s1,x2) & Actor(e2,x4) & v_smile(e2) & n_boy(x4) & on(e1,x2) & Actor(e1,x1) & v_sit(e1) & n_boy(x1))
exists e1 x1 x2.(n_horse(x2) & of(x2,x1) & n_male(x1) & n_boy(x1) & at(e1,x2) & Actor(e1,x1) & v_smile(e1))