A happy couple waving bye from the car.
a gril is sittting with his mother in living room
There can either be a couple or a girl. The girl would not be "his". One is waving from a car, the other is sitting in a living room.
exists e1 s1 x1 x2 x3 x4.(n_car(x4) & a_topic(x1) & from(e1,x4) & Theme(e1,x3) & Actor(e1,x2) & v_wave(e1) & n_bye(x3) & (x1 = x2) & n_couple(x1) & a_happy(s1) & Theme(s1,x1))
exists e1 x1 x2 x3 x4.(in(e1,x3) & n_room(x3) & of(x3,x4) & n_living(x4) & with(e1,x2) & n_mother(x2) & of(x2,x1) & n_male(x1) & Actor(e1,x1) & v_sittt(e1) & n_gril(x1))