A man sitting on a subway.
A man is riding the subway.
A man is sitting and riding on a subway.
exists e1 x1 x2 x3.(a_topic(x1) & on(e1,x3) & n_subway(x3) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_man(x1))
exists e1 x1 x2.(n_subway(x2) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_man(x1))