A man skies on snow with mountains in the background.
A man tubing on snow with mountains in the background.
If he skies, he cannot be tubing at the same time.
exists e1 x1 x2 x3 x4.(n_background(x4) & on(e1,x2) & with(x2,x3) & in(x3,x4) & n_mountain(x3) & n_snow(x2) & Actor(e1,x1) & v_sky(e1) & n_man(x1))
exists e1 x1 x2 x3 x4 x5.(n_background(x5) & a_topic(x1) & on(e1,x3) & with(x3,x4) & in(x4,x5) & n_mountain(x4) & n_snow(x3) & Actor(e1,x2) & v_tube(e1) & (x1 = x2) & n_man(x1))