WORST_CASE(?,O(n^2))
* Step 1: NaturalPI WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            f(cons(x,k),l) -> g(k,l,cons(x,k))
            f(empty(),l) -> l
            g(a,b,c) -> f(a,cons(b,c))
        - Signature:
            {f/2,g/3} / {cons/2,empty/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {f,g} and constructors {cons,empty}
    + Applied Processor:
        NaturalPI {shape = Quadratic, restrict = NoRestrict, uargs = UArgs, urules = URules, selector = Nothing}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(quadratic):
        The following argument positions are considered usable:
          none
        
        Following symbols are considered usable:
          {f,g}
        TcT has computed the following interpretation:
           p(cons) = 2 + x2              
          p(empty) = 0                   
              p(f) = 1 + x1 + x1^2 + x2  
              p(g) = 4 + 2*x1 + x1^2 + x3
        
        Following rules are strictly oriented:
        f(cons(x,k),l) = 7 + 5*k + k^2 + l
                       > 6 + 3*k + k^2    
                       = g(k,l,cons(x,k)) 
        
          f(empty(),l) = 1 + l            
                       > l                
                       = l                
        
              g(a,b,c) = 4 + 2*a + a^2 + c
                       > 3 + a + a^2 + c  
                       = f(a,cons(b,c))   
        
        
        Following rules are (at-least) weakly oriented:
        

WORST_CASE(?,O(n^2))