YES(?,ELEMENTARY)

'epo* (timeout of 60.0 seconds)'
--------------------------------
Answer:           YES(?,ELEMENTARY)
Input Problem:    innermost runtime-complexity with respect to
  Rules: {f(g(X)) -> f(X)}

Proof Output:    
  Strict Rules in Predicative Notation:
   {f(g(; X);) -> f(X;)}
  Safe Mapping:
   safe(f) = {}, safe(g) = {1}
  Argument Permutation:
   mu(f) = [1]
  Precedence:
   f ~ f