A white dog with a collar is running.
A white dog is chasing a thief.
Just because a dog is running it does not mean the dog is chasing a thief.
exists e1 s1 x1 x2.(Actor(e1,x1) & v_run(e1) & with(x1,x2) & n_collar(x2) & n_dog(x1) & a_white(s1) & Theme(s1,x1))
exists e1 s1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_chase(e1) & n_thief(x2) & n_dog(x1) & a_white(s1) & Theme(s1,x1))