A small boy is playing with rocks
a boy is having a great time playing with pebbles
We cannot assume the boy is having  a great time playing.
exists e1 s1 x1 x2.(with(e1,x2) & n_rock(x2) & Actor(e1,x1) & v_play(e1) & n_boy(x1) & a_small(s1) & Theme(s1,x1))
exists e1 e2 s1 x1 x2 x3 x4.(Theme(e2,x2) & Actor(e2,x1) & v_have(e2) & with(e1,x4) & n_pebble(x4) & Actor(e1,x3) & v_play(e1) & (x2 = x3) & n_time(x2) & a_great(s1) & Theme(s1,x2) & n_boy(x1))