A small boy dances on the concrete surrounded by adults.
A boy is dancing on a floor with older people in a circle around him
On a floor implies something different than on the concrete.  Surrounded by adults does not necessarily mean they are in a circle around him.
exists e1 s1 x1 x2 x3 x4 x5.(n_concrete(x3) & a_topic(x1) & on(x1,x3) & Actor(e1,x5) & n_adult(x5) & Theme(e1,x4) & v_surround(e1) & (x3 = x4) & n_dance(x1) & of(x1,x2) & n_boy(x2) & a_small(s1) & Theme(s1,x1))
exists e1 s1 x1 x2 x3 x4.(around(e1,x1) & n_male(x1) & in(e1,x4) & n_circle(x4) & with(e1,x3) & n_people(x3) & r_more(s1) & a_older(s1) & Theme(s1,x3) & on(e1,x2) & n_floor(x2) & Actor(e1,x1) & v_dance(e1) & n_boy(x1))