The boys smiles underwater at the pool.
Small boys smile and give a thumbs up under water at a public pool.
Boys don't need to give a thumbs up to smile underwater. The pool is not necessarily a public pool.
exists e1 x1 x2 x3.(n_pool(x3) & n_boy(x1) & at(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_smile(e1) & n_underwater(x2))
exists e1 e2 s1 s2 s3 s4 x1 x2 x3 x4 x5.(at(e2,x5) & n_pool(x5) & a_public(s4) & Theme(s4,x5) & a_up(s3) & Manner(e2,s3) & under(e2,x4) & n_water(x4) & Theme(e2,x3) & Actor(e2,x2) & v_give(e2) & n_thumb(x3) & n_boy(x2) & a_small(s2) & Theme(s2,x2) & Actor(e1,x1) & v_smile(e1) & n_boy(x1) & a_small(s1) & Theme(s1,x1))