three children spend time laughing on the couch.
the child is black
The first sentence does not mention that the children are black.
exists e1 p1 x1 x2 x3.(n_couch(x3) & exists e2.(on(e2,x3) & Actor(e2,x2) & v_laugh(e2)) & Recipient(e1,p1) & Actor(e1,x1) & Topic(e1,x2) & v_spend(e1) & n_time(x2) & n_child(x1) & card_eq_3(x1))
exists s1 x1.(n_child(x1) & Theme(s1,x1) & a_black(s1))