A child plays on the ground in a pile of leaves.
the child is a boy
The child isn't necessarily a boy. The child could also be a girl.
exists e1 x1 x2 x3 x4.(n_ground(x2) & on(e1,x2) & in(x2,x3) & of(x3,x4) & n_leaf(x4) & n_pile(x3) & Actor(e1,x1) & v_play(e1) & n_child(x1))
exists p1 x1.(n_child(x1) & exists x2.((x1 = x2) & n_boy(x2)))