Children playing checkers.
Children are smiling while they play a game.
It can't be inferred from sentence 1 that the children are smiling.
exists e1 x1 x2 x3.(a_topic(x1) & Theme(e1,x3) & Actor(e1,x2) & v_play(e1) & n_checkers(x3) & (x1 = x2) & n_child(x1))
exists e1 p1 x1.(exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_play(e2) & n_game(x2)) & n_thing(x1) & while(e1,p1) & Actor(e1,x1) & v_smile(e1) & n_child(x1))