A man talks on a cellphone while sitting on a stoop.
A man on a cellphone is standing in front of the stoop.
One cannot be sitting and standing at the same time.
(x)
exists e1 x1 x2 x3 x4.(n_stoop(x4) & in(e1,x3) & of(x3,x4) & n_front(x3) & Actor(e1,x1) & v_stand(e1) & on(x1,x2) & n_cellphone(x2) & n_man(x1))