A gray dog runs along the green grass.
The dog is running to catch something.
A gray dog running along the green grass is not necessarily running to catch something.
exists e1 s1 s2 x1 x2.(n_grass(x2) & a_green(s2) & Theme(s2,x2) & along(e1,x2) & Actor(e1,x1) & v_run(e1) & n_dog(x1) & a_gray(s1) & Theme(s1,x1))
exists e1 p1 x1.(n_dog(x1) & Topic(e1,p1) & exists e2 x2.(Theme(e2,x2) & Actor(e2,x1) & v_catch(e2) & n_thing(x2)) & Actor(e1,x1) & v_run(e1))