WORST_CASE(?,O(n^1))
* Step 1: Ara WORST_CASE(?,O(n^1))
    + Considered Problem:
        - Strict TRS:
            append(l1,l2) -> ifappend(l1,l2,l1)
            hd(cons(x,l)) -> x
            ifappend(l1,l2,cons(x,l)) -> cons(x,append(l,l2))
            ifappend(l1,l2,nil()) -> l2
            is_empty(cons(x,l)) -> false()
            is_empty(nil()) -> true()
            tl(cons(x,l)) -> l
        - Signature:
            {append/2,hd/1,ifappend/3,is_empty/1,tl/1} / {cons/2,false/0,nil/0,true/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {append,hd,ifappend,is_empty,tl} and constructors {cons
            ,false,nil,true}
    + Applied Processor:
        Ara {araHeuristics = NoHeuristics, minDegree = 1, maxDegree = 2, araTimeout = 5, araRuleShifting = Nothing}
    + Details:
        Signatures used:
        ----------------
          append :: ["A"(15) x "A"(14)] -(8)-> "A"(0)
          cons :: ["A"(0) x "A"(15)] -(15)-> "A"(15)
          cons :: ["A"(0) x "A"(11)] -(11)-> "A"(11)
          cons :: ["A"(0) x "A"(10)] -(10)-> "A"(10)
          cons :: ["A"(0) x "A"(0)] -(0)-> "A"(0)
          false :: [] -(0)-> "A"(14)
          hd :: ["A"(15)] -(0)-> "A"(0)
          ifappend :: ["A"(0) x "A"(14) x "A"(15)] -(3)-> "A"(0)
          is_empty :: ["A"(11)] -(1)-> "A"(0)
          nil :: [] -(0)-> "A"(15)
          nil :: [] -(0)-> "A"(11)
          tl :: ["A"(10)] -(15)-> "A"(0)
          true :: [] -(0)-> "A"(14)
        
        
        Cost-free Signatures used:
        --------------------------
        
        
        
        Base Constructor Signatures used:
        ---------------------------------
          "cons_A" :: ["A"(0) x "A"(1)] -(1)-> "A"(1)
          "false_A" :: [] -(0)-> "A"(1)
          "nil_A" :: [] -(0)-> "A"(1)
          "true_A" :: [] -(0)-> "A"(1)
        

WORST_CASE(?,O(n^1))