WORST_CASE(?,O(n^1))
* Step 1: NaturalPI WORST_CASE(?,O(n^1))
    + Considered Problem:
        - Strict TRS:
            f(X,X) -> c(X)
            f(X,c(X)) -> f(s(X),X)
            f(s(X),X) -> f(X,a(X))
        - Signature:
            {f/2} / {a/1,c/1,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {f} and constructors {a,c,s}
    + Applied Processor:
        NaturalPI {shape = StronglyLinear, restrict = NoRestrict, uargs = UArgs, urules = URules, selector = Nothing}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(stronglyLinear):
        The following argument positions are considered usable:
          none
        
        Following symbols are considered usable:
          {f}
        TcT has computed the following interpretation:
          p(a) = 0           
          p(c) = 9           
          p(f) = 12 + x1 + x2
          p(s) = 4           
        
        Following rules are strictly oriented:
           f(X,X) = 12 + 2*X 
                  > 9        
                  = c(X)     
        
        f(X,c(X)) = 21 + X   
                  > 16 + X   
                  = f(s(X),X)
        
        f(s(X),X) = 16 + X   
                  > 12 + X   
                  = f(X,a(X))
        
        
        Following rules are (at-least) weakly oriented:
        

WORST_CASE(?,O(n^1))