A woman wearing a backpack walks on the sidewalk while a car drives by.
the woman is waving at the car.
Woman on the side walk is just walking. There is no mention of her waving at the car.
exists e2 e1 s1 x1 x2 x3 x4 x5 x6.(n_sidewalk(x4) & a_by(s1) & Manner(e2,s1) & while(e2,x5) & n_drive(x5) & of(x5,x6) & n_car(x6) & on(e2,x4) & Actor(e2,x1) & v_walk(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & n_backpack(x3) & (x1 = x2) & n_woman(x1))
exists e1 x1 x2.(n_car(x2) & n_woman(x1) & at(e1,x2) & Actor(e1,x1) & v_wave(e1))