A dog running on grass.
A dog runs for an hour.
The dog may not be running for an hour. Most dogs tire before then.
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_grass(x3) & Actor(e1,x2) & v_run(e1) & (x1 = x2) & n_dog(x1))
exists e1 x1 x2.(for(e1,x2) & n_hour(x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1))