A depressed man sitting on a subway train.
A man is sitting on the subway riding to his job.
A man just sitting on the subway train  does'nt mean that he is riding to his job, he can go anywhere.
exists e1 s1 x1 x2 x3 x4.(a_topic(x1) & on(e1,x3) & n_train(x3) & of(x3,x4) & n_subway(x4) & Actor(e1,x2) & v_sit(e1) & (x1 = x2) & n_man(x1) & a_depressed(s1) & Theme(s1,x1))
exists e1 x1 x2 x3 x4.(n_job(x4) & of(x4,x2) & n_male(x2) & n_riding(x2) & of(x2,x3) & n_subway(x3) & on(e1,x2) & to(x2,x4) & Actor(e1,x1) & v_sit(e1) & n_man(x1))