TIMEOUT

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

Strict Trs:
  { a__first(X1, X2) -> first(X1, X2)
  , a__first(0(), X) -> nil()
  , a__first(s(X), cons(Y, Z)) -> cons(mark(Y), first(X, Z))
  , mark(0()) -> 0()
  , mark(nil()) -> nil()
  , mark(s(X)) -> s(mark(X))
  , mark(cons(X1, X2)) -> cons(mark(X1), X2)
  , mark(first(X1, X2)) -> a__first(mark(X1), mark(X2))
  , mark(from(X)) -> a__from(mark(X))
  , a__from(X) -> cons(mark(X), from(s(X)))
  , a__from(X) -> from(X) }
Obligation:
  innermost runtime complexity
Answer:
  TIMEOUT

Computation stopped due to timeout after 10.0 seconds.

Arrrr..