Several brown dogs of different sizes gather together.
The dogs are playing at the dog park.
Just because several dogs are together it doesn't mean that they are playing. They could be lounging around. Just because dogs are together it doesn't mean they are at the dog park. They could be in a yard or out in the woods.
exists e1 p1 s1 s2 x1 x2 x3.(n_size(x3) & exists s3.(Theme(s3,x1) & a_together(s3)) & Topic(e1,p1) & Actor(e1,x1) & v_gather(e1) & of(x1,x2) & -(x2 = x3) & n_size(x2) & n_dog(x1) & a_brown(s2) & Theme(s2,x1) & a_several(s1) & Theme(s1,x1))
exists e1 x1 x2.(n_park(x2) & of(x2,x1) & n_dog(x1) & n_dog(x1) & at(e1,x2) & Actor(e1,x1) & v_play(e1))