A group of girls sit back to back.
Some girls are resting against each other.
The girls could be working out sitting back to back, not just resting
exists e1 s1 x1 x2 x3.(Theme(e1,s1) & Theme(s1,x3) & a_back(s1) & r_back(e1) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & n_girl(x2) & n_group(x1))
exists e1 x1.(all x2.(n_other(x2) -> against(e1,x2)) & Actor(e1,x1) & v_rest(e1) & n_girl(x1))