A woman sitting in the passenger side of a car is waving.
The woman is waiving to her son.
There is no mention of who the woman is waving to so we do not know is is her son.
exists e2 e1 x1 x2 x3 x4 x5.(n_side(x3) & of(x3,x4) & n_passenger(x4) & Actor(e2,x1) & v_wave(e2) & in(e1,x3) & of(x3,x5) & n_car(x5) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_woman(x1))
exists e1 x1 x2.(n_son(x2) & of(x2,x1) & n_female(x1) & n_woman(x1) & to(e1,x2) & Actor(e1,x1) & v_waive(e1))