Two people in the water while two other people are jumping out of the water.
The people are playing by a pool.
Water exists outside of pool, such as lakes and rivers, people can play in these too.
(x)
exists e1 x1 x2.(n_people(x1) & by(e1,x2) & n_pool(x2) & Actor(e1,x1) & v_play(e1))