A shoeshine man sits on his stool in front of an empty seat.
The man is polishing a shoe.
The man cannot be polishing a shoe, if no-one is sitting in the seat in front of him.
exists e1 s1 x1 x2 x3 x4 x5.(in(e1,x4) & of(x4,x5) & n_seat(x5) & a_empty(s1) & Theme(s1,x5) & n_front(x4) & on(e1,x3) & n_stool(x3) & of(x3,x1) & n_male(x1) & Actor(e1,x1) & v_sit(e1) & n_man(x1) & of(x1,x2) & n_shoeshine(x2))
exists e1 x1 x2.(n_man(x1) & Theme(e1,x2) & Actor(e1,x1) & v_polish(e1) & n_shoe(x2))