TIMEOUT
MAYBE
Trs:
 {    rev(rev(x)) -> x,
    rev(++(x, y)) -> ++(rev(y), rev(x)),
       rev(nil()) -> nil(),
     ++(nil(), y) -> y,
   ++(.(x, y), z) -> .(x, ++(y, z)),
  ++(x, ++(y, z)) -> ++(++(x, y), z),
     ++(x, nil()) -> x,
          make(x) -> .(x, nil())}
 Open