Old person is sitting on a sidewalk with a cane.
The teenager walks along the sidewalk.
old person is contradictory to teenager
exists e1 x1 x2 x3 x4.(with(e1,x4) & n_cane(x4) & on(e1,x3) & n_sidewalk(x3) & Actor(e1,x1) & v_sit(e1) & n_person(x1) & (x1 = x2) & ne_nam_old(x2))
exists e1 x1 x2.(n_sidewalk(x2) & n_teenager(x1) & along(e1,x2) & Actor(e1,x1) & v_walk(e1))