A dog runs in the snow.
The dog is sitting.
a dog can not be running if it is sitting
exists e1 x1 x2.(n_snow(x2) & in(e1,x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1))
exists e1 x1.(n_dog(x1) & Actor(e1,x1) & v_sit(e1))