A group of ladies with computers sit behind a table while people on the other side purchase something.
Some people buy food from some cashiers.
Purchasing something doesn't necessarily imply that it is food, or that the ladies with computers are cashiers.
exists e1 s1 x1 x2 x3 x4 x5 x6 x7 x8.(-(x6 = x6) & n_purchase(x6) & of(x6,x8) & n_side(x8) & of(x6,x7) & n_side(x7) & a_something(s1) & Manner(e1,s1) & on(e1,x6) & while(e1,x5) & n_people(x5) & behind(e1,x4) & n_table(x4) & Actor(e1,x1) & v_sit(e1) & of(x1,x2) & with(x2,x3) & n_computer(x3) & n_lady(x2) & n_group(x1))
exists e1 x1 x2 x3.(from(e1,x3) & n_cashier(x3) & Theme(e1,x2) & Actor(e1,x1) & v_buy(e1) & n_food(x2) & n_people(x1))