A fluffy dog in grass.
a dog happily playing in the grass
Just because the dog is in the grass doesn't make him happy. There is also no indication that he is playing.
exists s1 x1 x2.(a_topic(x1) & in(x1,x2) & n_grass(x2) & n_dog(x1) & a_fluffy(s1) & Theme(s1,x1))
exists e1 s1 x1 x2 x3.(n_grass(x3) & a_topic(x1) & a_happily(s1) & Manner(e1,s1) & in(e1,x3) & Actor(e1,x2) & v_play(e1) & (x1 = x2) & n_dog(x1))