A boy plays in the sand.
A boy is playing in the snow.
It is not normal to play in sand and snow at the same time.
exists e1 x1 x2.(n_sand(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1))
exists e1 x1 x2.(n_snow(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1))