The students sitting on the grass are eating a lunch from a red backpack.
People are at a bar.
One cannot be sitting on the grass eating lunch and at a bar at the same time.
exists e2 e1 s1 x1 x2 x3 x4 x5.(n_grass(x3) & n_student(x1) & Theme(e2,x4) & Actor(e2,x1) & v_eat(e2) & from(x4,x5) & n_backpack(x5) & a_red(s1) & Theme(s1,x5) & n_lunch(x4) & on(e1,x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2))
exists p1 x1.(exists x2.(at(x1,x2) & n_bar(x2)) & n_people(x1))