MAYBE

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

Strict Trs:
  { and(tt(), tt()) -> tt()
  , is_nat(0()) -> tt()
  , is_nat(s(x)) -> is_nat(x)
  , is_natlist(nil()) -> tt()
  , is_natlist(cons(x, xs)) -> and(is_nat(x), is_natlist(xs))
  , from(x) -> fromCond(is_natlist(x), x)
  , fromCond(tt(), cons(x, xs)) -> from(cons(s(x), cons(x, xs))) }
Obligation:
  innermost runtime complexity
Answer:
  MAYBE

The input cannot be shown compatible

Arrrr..