A man is standing while riding the bus.
There is a man in the bus.
Riding the bus involves being in the bus.
exists e1 e2 x1 x2.(n_bus(x2) & while(e1,e2) & Theme(e2,x2) & Actor(e2,x1) & v_ride(e2) & Actor(e1,x1) & v_stand(e1) & n_man(x1))
exists p1 x1 x3.(n_bus(x3) & exists x2.((x1 = x2) & in(x2,x3) & n_man(x2)))