MAYBE

We are left with following problem, upon which TcT provides the
certificate MAYBE.

Strict Trs:
  { a__from(X) -> cons(mark(X), from(s(X)))
  , a__from(X) -> from(X)
  , mark(cons(X1, X2)) -> cons(mark(X1), X2)
  , mark(from(X)) -> a__from(mark(X))
  , mark(s(X)) -> s(mark(X))
  , mark(nil()) -> nil()
  , mark(0()) -> 0()
  , mark(length(X)) -> a__length(X)
  , mark(length1(X)) -> a__length1(X)
  , a__length(X) -> length(X)
  , a__length(cons(X, Y)) -> s(a__length1(Y))
  , a__length(nil()) -> 0()
  , a__length1(X) -> a__length(X)
  , a__length1(X) -> length1(X) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..