A lot of people are attending an aviation exposition.
Many people are riding a train.
Riding a train is not attending an expo.
exists e1 x1 x2 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_attend(e1) & n_exposition(x3) & of(x3,x4) & n_aviation(x4) & of(x1,x2) & n_people(x2) & n_lot(x1))
exists e1 x1 x2.(Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_train(x2) & n_people(x1) & n_quantity(x1))