The snowboarder is sitting down.
The snowboarder is standing.
The snowboarder cannot be sitting down as well as standing at the same time.
exists e1 s1 x1.(n_snowboarder(x1) & a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1))
exists e1 x1.(n_snowboarder(x1) & Actor(e1,x1) & v_stand(e1))