A male passenger listens to an iPod, while riding a train.
A passenger listening to music in the train.
Listening to an iPod implies he is  listening to music.
exists e1 e2 s1 x1 x2 x3.(while(e1,e2) & Theme(e2,x3) & Actor(e2,x1) & v_ride(e2) & n_train(x3) & to(e1,x2) & n_ipod(x2) & Actor(e1,x1) & v_listen(e1) & n_passenger(x1) & a_male(s1) & Theme(s1,x1))
exists x1 x2 x3 x4.(n_train(x4) & a_topic(x1) & to(x1,x3) & in(x3,x4) & n_music(x3) & n_listening(x1) & of(x1,x2) & n_passenger(x2))