A dog jumps over a hurdle in the grass.
A dog is sleeping in the sand.
One cannot be jumping and sleeping simultaneously.
exists e1 x1 x2 x3.(n_grass(x3) & over(e1,x2) & in(x2,x3) & n_hurdle(x2) & Actor(e1,x1) & v_jump(e1) & n_dog(x1))
exists e1 x1 x2.(n_sand(x2) & in(e1,x2) & Actor(e1,x1) & v_sleep(e1) & n_dog(x1))