MAYBE

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

Strict Trs:
  { from(X) -> cons(X, from(s(X)))
  , first(s(X), cons(Y, Z)) -> cons(Y, first(X, Z))
  , first(0(), Z) -> nil()
  , sel(s(X), cons(Y, Z)) -> sel(X, Z)
  , sel(0(), cons(X, Z)) -> X }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..