WORST_CASE(?,O(n^1))
* Step 1: Ara WORST_CASE(?,O(n^1))
    + Considered Problem:
        - Strict TRS:
            activate(X) -> X
            activate(n__add(X1,X2)) -> add(X1,X2)
            activate(n__from(X)) -> from(X)
            activate(n__fst(X1,X2)) -> fst(X1,X2)
            activate(n__len(X)) -> len(X)
            add(X1,X2) -> n__add(X1,X2)
            add(0(),X) -> X
            add(s(X),Y) -> s(n__add(activate(X),Y))
            from(X) -> cons(X,n__from(s(X)))
            from(X) -> n__from(X)
            fst(X1,X2) -> n__fst(X1,X2)
            fst(0(),Z) -> nil()
            fst(s(X),cons(Y,Z)) -> cons(Y,n__fst(activate(X),activate(Z)))
            len(X) -> n__len(X)
            len(cons(X,Z)) -> s(n__len(activate(Z)))
            len(nil()) -> 0()
        - Signature:
            {activate/1,add/2,from/1,fst/2,len/1} / {0/0,cons/2,n__add/2,n__from/1,n__fst/2,n__len/1,nil/0,s/1}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {activate,add,from,fst,len} and constructors {0,cons
            ,n__add,n__from,n__fst,n__len,nil,s}
    + Applied Processor:
        Ara {araHeuristics = NoHeuristics, minDegree = 1, maxDegree = 2, araTimeout = 5, araRuleShifting = Nothing}
    + Details:
        Signatures used:
        ----------------
          0 :: [] -(0)-> "A"(3)
          0 :: [] -(0)-> "A"(6)
          activate :: ["A"(3)] -(6)-> "A"(0)
          add :: ["A"(3) x "A"(1)] -(8)-> "A"(0)
          cons :: ["A"(3) x "A"(3)] -(3)-> "A"(3)
          cons :: ["A"(0) x "A"(0)] -(0)-> "A"(0)
          from :: ["A"(1)] -(8)-> "A"(0)
          fst :: ["A"(3) x "A"(3)] -(8)-> "A"(0)
          len :: ["A"(3)] -(4)-> "A"(0)
          n__add :: ["A"(3) x "A"(3)] -(3)-> "A"(3)
          n__add :: ["A"(1) x "A"(1)] -(1)-> "A"(1)
          n__add :: ["A"(0) x "A"(0)] -(0)-> "A"(0)
          n__from :: ["A"(3)] -(3)-> "A"(3)
          n__from :: ["A"(1)] -(1)-> "A"(1)
          n__from :: ["A"(0)] -(0)-> "A"(0)
          n__fst :: ["A"(3) x "A"(3)] -(3)-> "A"(3)
          n__fst :: ["A"(2) x "A"(2)] -(2)-> "A"(2)
          n__fst :: ["A"(0) x "A"(0)] -(0)-> "A"(0)
          n__len :: ["A"(3)] -(0)-> "A"(3)
          n__len :: ["A"(1)] -(0)-> "A"(1)
          n__len :: ["A"(0)] -(0)-> "A"(0)
          nil :: [] -(0)-> "A"(3)
          nil :: [] -(0)-> "A"(7)
          s :: ["A"(3)] -(3)-> "A"(3)
          s :: ["A"(0)] -(0)-> "A"(0)
          s :: ["A"(1)] -(1)-> "A"(1)
        
        
        Cost-free Signatures used:
        --------------------------
        
        
        
        Base Constructor Signatures used:
        ---------------------------------
          "0_A" :: [] -(0)-> "A"(1)
          "cons_A" :: ["A"(1) x "A"(1)] -(1)-> "A"(1)
          "n__add_A" :: ["A"(0) x "A"(0)] -(1)-> "A"(1)
          "n__from_A" :: ["A"(0)] -(1)-> "A"(1)
          "n__fst_A" :: ["A"(0) x "A"(0)] -(1)-> "A"(1)
          "n__len_A" :: ["A"(0)] -(0)-> "A"(1)
          "nil_A" :: [] -(0)-> "A"(1)
          "s_A" :: ["A"(1)] -(1)-> "A"(1)
        

WORST_CASE(?,O(n^1))