Two boys playing in the shadows of the trees.
Some kids are sitting by a lake
One cannot be sitting by a lake and playing in the shadows of the trees at the same time.
exists e1 x1 x2 x3 x4.(n_tree(x4) & n_shadow(x3) & a_topic(x1) & in(e1,x3) & of(x3,x4) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_boy(x1) & card_eq_2(x1))
exists e1 x1 x2.(by(e1,x2) & n_lake(x2) & Actor(e1,x1) & v_sit(e1) & n_kid(x1))