TRS:
 {a__2nd(cons(X, cons(Y, Z))) -> mark(Y),
                   a__from(X) -> cons(mark(X), from(s(X))),
                 mark(2nd(X)) -> a__2nd(mark(X)),
                mark(from(X)) -> a__from(mark(X)),
           mark(cons(X1, X2)) -> cons(mark(X1), X2),
                   mark(s(X)) -> s(mark(X)),
                    a__2nd(X) -> 2nd(X),
                   a__from(X) -> from(X)}
 Fail