A man is standing while riding the bus.
A man is sitting while riding the bus.
The man is either sitting or standing.
exists e2 e1 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 e2 e1 x1 x2.(n_bus(x2) & while(e1,e2) & Theme(e2,x2) & Actor(e2,x1) & v_ride(e2) & Actor(e1,x1) & v_sit(e1) & n_man(x1))