A man playing with a small child in a pool.
A man is playing with his son.
small child  doesn't always mean  son.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & in(e1,x4) & n_pool(x4) & with(e1,x3) & n_child(x3) & a_small(s1) & Theme(s1,x3) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_man(x1))
exists e1 x1 x2.(with(e1,x2) & n_son(x2) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_play(e1) & n_man(x1))