A person stands atop a rock face.
The person is sitting down
One cannot be standing and sitting simultaneously.
exists e1 x1 x2 x3.(atop(e1,x2) & n_face(x2) & of(x2,x3) & n_rock(x3) & Actor(e1,x1) & v_stand(e1) & n_person(x1))
exists e1 s1 x1.(n_person(x1) & a_down(s1) & Manner(e1,s1) & Actor(e1,x1) & v_sit(e1))