Several people in a crowded commuter train.
People in a commuter train.
Both sentences state people are on a commuter train.
exists s1 s2 x1 x2 x3.(a_topic(x1) & in(x1,x2) & n_train(x2) & of(x2,x3) & n_commuter(x3) & a_crowded(s2) & Theme(s2,x2) & n_people(x1) & a_several(s1) & Theme(s1,x1))
exists x1 x2 x3.(a_topic(x1) & in(x1,x2) & n_train(x2) & of(x2,x3) & n_commuter(x3) & n_people(x1))