A male walks on the graffiti wall.
Someone walks on a wall.
The male walking on the graffiti wall is walking on the wall.
exists e1 x1 x2 x3.(n_wall(x2) & of(x2,x3) & n_graffitus(x3) & on(e1,x2) & Actor(e1,x1) & v_walk(e1) & n_male(x1))
exists e1 x1 x2.(on(e1,x2) & n_wall(x2) & Actor(e1,x1) & v_walk(e1) & n_person(x1))