A man is reading a newspaper on a crowded subway train.
A man is on a boat.
A man is on a crowded subway train.  A man is not on a boat.
exists e1 s1 x1 x2 x3 x4.(on(e1,x3) & n_train(x3) & of(x3,x4) & n_subway(x4) & a_crowded(s1) & Theme(s1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_read(e1) & n_newspaper(x2) & n_man(x1))
exists p1 x1.(exists x2.(on(x1,x2) & n_boat(x2)) & n_man(x1))