A girls is jumping in the sand.
The girl is jumping around in the sand.
a girls refer to the girl.
exists e1 x1 x2.(n_sand(x2) & in(e1,x2) & Actor(e1,x1) & v_jump(e1) & n_girl(x1))
exists e1 s1 x1 x2.(n_sand(x2) & n_girl(x1) & in(e1,x2) & a_around(s1) & Manner(e1,s1) & Actor(e1,x1) & v_jump(e1))