YES(?,PRIMREC)

We are left with following problem, upon which TcT provides the
certificate YES(?,PRIMREC).

Strict Trs:
  { a__f(X) -> g(h(f(X)))
  , a__f(X) -> f(X)
  , mark(g(X)) -> g(X)
  , mark(h(X)) -> h(mark(X))
  , mark(f(X)) -> a__f(mark(X)) }
Obligation:
  innermost runtime complexity
Answer:
  YES(?,PRIMREC)

The input was oriented with the instance of'multiset path order' as
induced by the precedence

 a__f > g, a__f > h, a__f > f, mark > a__f, mark > g, mark > h,
 mark > f, g ~ h, g ~ f, h ~ f .

Hurray, we answered YES(?,PRIMREC)