A photographer takes pictures of a wall covered in graffiti.
The photographer is using a tripod.
Just because the photographer takes pictures of a wall doesn't mean that hi  is using a tripod.
exists e1 e2 x1 x2 x3 x4 x5.(Theme(e2,x2) & Actor(e2,x1) & v_take(e2) & of(x2,x3) & in(e1,x5) & n_graffitus(x5) & Theme(e1,x4) & v_cover(e1) & (x3 = x4) & n_wall(x3) & n_picture(x2) & n_photographer(x1))
exists e1 x1 x2.(n_photographer(x1) & Theme(e1,x2) & Actor(e1,x1) & v_use(e1) & n_tripod(x2))