A man sells food from a cart on the street while pedestrians walk past.
There are no pedestrians.
Pedestrians versus no pedestrians.
exists e1 p1 x1 x2 x3 x4.(n_street(x4) & exists e2 x5 x6.(Time(e2,x6) & n_past(x6) & Actor(e2,x5) & v_walk(e2) & n_pedestrian(x5)) & while(e1,p1) & from(e1,x3) & on(x3,x4) & n_cart(x3) & Theme(e1,x2) & Actor(e1,x1) & v_sell(e1) & n_food(x2) & n_man(x1))
exists p1 x1.-exists x2.((x1 = x2) & n_pedestrian(x2))