Children smiling and waving at camera
The kids are frowning
One cannot be smiling and frowning at the same time.
exists e2 e1 x1 x2.(ne_nam_children(x1) & at(e2,x2) & n_camera(x2) & Actor(e2,x1) & v_wave(e2) & Actor(e1,x1) & v_smile(e1))
exists e1 x1.(n_kid(x1) & Actor(e1,x1) & v_frown(e1))