The young child in green pants is playing in the sand.
a child is playing in the sand
Sentence two is merely a reconfirmation of sentence one.  There is a child playing in the sand.
exists e1 s1 s2 x1 x2 x3.(n_sand(x3) & n_child(x1) & a_young(s1) & Theme(s1,x1) & in(e1,x3) & Actor(e1,x1) & v_play(e1) & in(x1,x2) & n_pants(x2) & a_green(s2) & Theme(s2,x2))
exists e1 x1 x2.(n_sand(x2) & in(e1,x2) & Actor(e1,x1) & v_play(e1) & n_child(x1))