WORST_CASE(?,O(n^1))
* Step 1: NaturalPI WORST_CASE(?,O(n^1))
    + Considered Problem:
        - Strict TRS:
            append(Cons(x,xs),ys) -> Cons(x,append(xs,ys))
            append(Nil(),ys) -> ys
            goal(x,y) -> append(x,y)
        - Signature:
            {append/2,goal/2} / {Cons/2,Nil/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {append,goal} and constructors {Cons,Nil}
    + Applied Processor:
        NaturalPI {shape = Linear, restrict = NoRestrict, uargs = UArgs, urules = URules, selector = Nothing}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(linear):
        The following argument positions are considered usable:
          uargs(Cons) = {2}
        
        Following symbols are considered usable:
          {append,goal}
        TcT has computed the following interpretation:
            p(Cons) = 5 + x1 + x2       
             p(Nil) = 2                 
          p(append) = 8 + 4*x1 + 12*x2  
            p(goal) = 13 + 13*x1 + 12*x2
        
        Following rules are strictly oriented:
        append(Cons(x,xs),ys) = 28 + 4*x + 4*xs + 12*ys
                              > 13 + x + 4*xs + 12*ys  
                              = Cons(x,append(xs,ys))  
        
             append(Nil(),ys) = 16 + 12*ys             
                              > ys                     
                              = ys                     
        
                    goal(x,y) = 13 + 13*x + 12*y       
                              > 8 + 4*x + 12*y         
                              = append(x,y)            
        
        
        Following rules are (at-least) weakly oriented:
        

WORST_CASE(?,O(n^1))