YES(?,ELEMENTARY)

'epo* (timeout of 60.0 seconds)'
--------------------------------
Answer:           YES(?,ELEMENTARY)
Input Problem:    innermost runtime-complexity with respect to
  Rules:
    {  p(0()) -> 0()
     , p(s(x)) -> x
     , minus(x, 0()) -> x
     , minus(x, s(y)) -> minus(p(x), y)}

Proof Output:    
  Strict Rules in Predicative Notation:
   {  p(; 0()) -> 0()
    , p(; s(; x)) -> x
    , minus(0(); x) -> x
    , minus(s(; y); x) -> minus(y; p(; x))}
  Safe Mapping:
   safe(p) = {1}, safe(0) = {}, safe(s) = {1}, safe(minus) = {1}
  Argument Permutation:
   mu(p) = [1], mu(minus) = [2, 1]
  Precedence:
   minus ~ minus, minus > p, p ~ p