YES(?,ELEMENTARY)

'epo* (timeout of 60.0 seconds)'
--------------------------------
Answer:           YES(?,ELEMENTARY)
Input Problem:    innermost runtime-complexity with respect to
  Rules:
    {  and(tt(), X) -> X
     , plus(N, 0()) -> N
     , plus(N, s(M)) -> s(plus(N, M))}

Proof Output:    
  Strict Rules in Predicative Notation:
   {  and(; tt(), X) -> X
    , plus(0(); N) -> N
    , plus(s(; M); N) -> s(; plus(M; N))}
  Safe Mapping:
   safe(and) = {1, 2}, safe(tt) = {}, safe(plus) = {1}, safe(0) = {},
   safe(s) = {1}
  Argument Permutation:
   mu(and) = [2, 1], mu(plus) = [2, 1]
  Precedence:
   plus ~ plus, plus > and, and ~ and