Three people are standing in an aisle between two shelving units stacked with books.
Some people are standing in an aisle between shelves.
You can not infer it is between shelves.
exists e1 e2 e3 x1 x2 x3 x4 x5.(in(e1,x2) & between(x2,x3) & with(e3,x5) & n_book(x5) & Theme(e3,x4) & v_stack(e3) & (x3 = x4) & n_unit(x3) & Actor(e2,x3) & v_shelve(e2) & card_eq_2(x3) & n_aisle(x2) & Actor(e1,x1) & v_stand(e1) & n_people(x1) & card_eq_3(x1))
exists e1 x1 x2 x3.(in(e1,x2) & between(x2,x3) & n_shelf(x3) & n_aisle(x2) & Actor(e1,x1) & v_stand(e1) & n_people(x1))