Oriental people are riding in a train.
There is nobody riding the train.
People are riding the train and then nobody is riding the train. The numbers are different.
exists e1 s1 x1 x2.(in(e1,x2) & n_train(x2) & Actor(e1,x1) & v_ride(e1) & n_people(x1) & a_oriental(s1) & Theme(s1,x1))
exists p1 x1 x4.(n_train(x4) & -exists e1 x2 x3.((x1 = x2) & Theme(e1,x4) & Actor(e1,x3) & v_ride(e1) & (x2 = x3) & n_person(x2)))