They swim laps across the pool.
Kids are playing in a pool.
kids are is
exists e1 x1 x2 x3.(n_pool(x3) & n_thing(x1) & Theme(e1,x2) & Actor(e1,x1) & v_swim(e1) & across(x2,x3) & n_lap(x2))
exists e1 x1 x2.(in(e1,x2) & n_pool(x2) & Actor(e1,x1) & v_play(e1) & n_kid(x1))