WORST_CASE(?,O(1))
* Step 1: Ara WORST_CASE(?,O(1))
    + Considered Problem:
        - Strict TRS:
            add(0(),X) -> X
            add(s(),Y) -> s()
            from(X) -> cons(X)
            fst(0(),Z) -> nil()
            fst(s(),cons(Y)) -> cons(Y)
            len(cons(X)) -> s()
            len(nil()) -> 0()
        - Signature:
            {add/2,from/1,fst/2,len/1} / {0/0,cons/1,nil/0,s/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {add,from,fst,len} and constructors {0,cons,nil,s}
    + Applied Processor:
        Ara {araHeuristics = Heuristics, minDegree = 1, maxDegree = 2, araTimeout = 3, araRuleShifting = Nothing}
    + Details:
        Signatures used:
        ----------------
          0 :: [] -(0)-> "A"(0)
          add :: ["A"(0) x "A"(0)] -(1)-> "A"(0)
          cons :: ["A"(0)] -(0)-> "A"(0)
          from :: ["A"(0)] -(1)-> "A"(0)
          fst :: ["A"(0) x "A"(0)] -(1)-> "A"(0)
          len :: ["A"(0)] -(1)-> "A"(0)
          nil :: [] -(0)-> "A"(0)
          s :: [] -(0)-> "A"(0)
        
        
        Cost-free Signatures used:
        --------------------------
        
        
        
        Base Constructor Signatures used:
        ---------------------------------
          "0_A" :: [] -(0)-> "A"(0)
          "cons_A" :: ["A"(0)] -(0)-> "A"(0)
          "nil_A" :: [] -(0)-> "A"(0)
          "s_A" :: [] -(0)-> "A"(0)
        

WORST_CASE(?,O(1))