WORST_CASE(?,O(n^2))
* Step 1: Ara WORST_CASE(?,O(n^2))
    + Considered Problem:
        - Strict TRS:
            append(@l1,@l2) -> append#1(@l1,@l2)
            append#1(::(@x,@xs),@l2) -> ::(@x,append(@xs,@l2))
            append#1(nil(),@l2) -> @l2
            appendAll(@l) -> appendAll#1(@l)
            appendAll#1(::(@l1,@ls)) -> append(@l1,appendAll(@ls))
            appendAll#1(nil()) -> nil()
            appendAll2(@l) -> appendAll2#1(@l)
            appendAll2#1(::(@l1,@ls)) -> append(appendAll(@l1),appendAll2(@ls))
            appendAll2#1(nil()) -> nil()
            appendAll3(@l) -> appendAll3#1(@l)
            appendAll3#1(::(@l1,@ls)) -> append(appendAll2(@l1),appendAll3(@ls))
            appendAll3#1(nil()) -> nil()
        - Signature:
            {append/2,append#1/2,appendAll/1,appendAll#1/1,appendAll2/1,appendAll2#1/1,appendAll3/1
            ,appendAll3#1/1} / {::/2,nil/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {append,append#1,appendAll,appendAll#1,appendAll2
            ,appendAll2#1,appendAll3,appendAll3#1} and constructors {::,nil}
    + Applied Processor:
        Ara {heuristics_ = NoHeuristics, minDegree = 1, maxDegree = 3, araTimeout = 60, araFindStrictRules = Nothing, araSmtSolver = Z3}
    + Details:
        Signatures used:
        ----------------
          :: :: [A(6, 0) x A(6, 0)] -(6)-> A(6, 0)
          :: :: [A(12, 7) x A(12, 7)] -(5)-> A(5, 7)
          :: :: [A(15, 8) x A(15, 8)] -(7)-> A(7, 8)
          :: :: [A(15, 9) x A(15, 9)] -(6)-> A(6, 9)
          :: :: [A(4, 0) x A(4, 0)] -(4)-> A(4, 0)
          append :: [A(6, 0) x A(4, 0)] -(2)-> A(4, 0)
          append#1 :: [A(6, 0) x A(4, 0)] -(1)-> A(4, 0)
          appendAll :: [A(9, 7)] -(2)-> A(6, 0)
          appendAll#1 :: [A(5, 7)] -(1)-> A(2, 0)
          appendAll2 :: [A(12, 8)] -(2)-> A(6, 0)
          appendAll2#1 :: [A(7, 8)] -(1)-> A(3, 0)
          appendAll3 :: [A(9, 9)] -(2)-> A(3, 0)
          appendAll3#1 :: [A(6, 9)] -(1)-> A(2, 0)
          nil :: [] -(0)-> A(6, 0)
          nil :: [] -(0)-> A(5, 7)
          nil :: [] -(0)-> A(7, 8)
          nil :: [] -(0)-> A(6, 9)
        
        
        Cost-free Signatures used:
        --------------------------
          :: :: [A_cf(0, 0) x A_cf(0, 0)] -(0)-> A_cf(0, 0)
          :: :: [A_cf(4, 0) x A_cf(4, 0)] -(4)-> A_cf(4, 0)
          :: :: [A_cf(3, 0) x A_cf(3, 0)] -(3)-> A_cf(3, 0)
          :: :: [A_cf(5, 0) x A_cf(5, 0)] -(5)-> A_cf(5, 0)
          :: :: [A_cf(1, 0) x A_cf(1, 0)] -(1)-> A_cf(1, 0)
          :: :: [A_cf(6, 0) x A_cf(6, 0)] -(6)-> A_cf(6, 0)
          append :: [A_cf(0, 0) x A_cf(0, 0)] -(0)-> A_cf(0, 0)
          append :: [A_cf(4, 0) x A_cf(4, 0)] -(0)-> A_cf(4, 0)
          append :: [A_cf(4, 0) x A_cf(3, 0)] -(4)-> A_cf(3, 0)
          append :: [A_cf(1, 0) x A_cf(1, 0)] -(0)-> A_cf(1, 0)
          append :: [A_cf(3, 0) x A_cf(1, 0)] -(5)-> A_cf(1, 0)
          append :: [A_cf(3, 0) x A_cf(3, 0)] -(0)-> A_cf(3, 0)
          append#1 :: [A_cf(0, 0) x A_cf(0, 0)] -(0)-> A_cf(0, 0)
          append#1 :: [A_cf(4, 0) x A_cf(4, 0)] -(0)-> A_cf(4, 0)
          append#1 :: [A_cf(4, 0) x A_cf(3, 0)] -(4)-> A_cf(3, 0)
          append#1 :: [A_cf(1, 0) x A_cf(1, 0)] -(0)-> A_cf(1, 0)
          append#1 :: [A_cf(3, 0) x A_cf(1, 0)] -(5)-> A_cf(1, 0)
          append#1 :: [A_cf(3, 0) x A_cf(3, 0)] -(0)-> A_cf(3, 0)
          appendAll :: [A_cf(4, 0)] -(1)-> A_cf(4, 0)
          appendAll :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
          appendAll :: [A_cf(4, 0)] -(0)-> A_cf(4, 0)
          appendAll :: [A_cf(1, 0)] -(0)-> A_cf(0, 0)
          appendAll :: [A_cf(1, 0)] -(0)-> A_cf(1, 0)
          appendAll :: [A_cf(3, 0)] -(0)-> A_cf(3, 0)
          appendAll#1 :: [A_cf(4, 0)] -(0)-> A_cf(4, 0)
          appendAll#1 :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
          appendAll#1 :: [A_cf(1, 0)] -(0)-> A_cf(0, 0)
          appendAll#1 :: [A_cf(1, 0)] -(0)-> A_cf(1, 0)
          appendAll#1 :: [A_cf(3, 0)] -(0)-> A_cf(3, 0)
          appendAll2 :: [A_cf(5, 0)] -(0)-> A_cf(3, 0)
          appendAll2 :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
          appendAll2 :: [A_cf(1, 0)] -(3)-> A_cf(1, 0)
          appendAll2 :: [A_cf(4, 0)] -(0)-> A_cf(3, 0)
          appendAll2#1 :: [A_cf(5, 0)] -(0)-> A_cf(3, 0)
          appendAll2#1 :: [A_cf(3, 0)] -(0)-> A_cf(0, 0)
          appendAll2#1 :: [A_cf(1, 0)] -(3)-> A_cf(1, 0)
          appendAll2#1 :: [A_cf(4, 0)] -(0)-> A_cf(3, 0)
          appendAll3 :: [A_cf(3, 0)] -(0)-> A_cf(1, 0)
          appendAll3 :: [A_cf(6, 0)] -(0)-> A_cf(1, 0)
          appendAll3#1 :: [A_cf(3, 0)] -(0)-> A_cf(1, 0)
          appendAll3#1 :: [A_cf(6, 0)] -(0)-> A_cf(1, 0)
          nil :: [] -(0)-> A_cf(0, 0)
          nil :: [] -(0)-> A_cf(4, 0)
          nil :: [] -(0)-> A_cf(7, 2)
          nil :: [] -(0)-> A_cf(3, 0)
          nil :: [] -(0)-> A_cf(3, 2)
          nil :: [] -(0)-> A_cf(5, 0)
          nil :: [] -(0)-> A_cf(1, 0)
          nil :: [] -(0)-> A_cf(1, 2)
          nil :: [] -(0)-> A_cf(6, 0)
        
        
        Base Constructor Signatures used:
        ---------------------------------
          ::_A :: [A(0) x A(0)] -(0)-> A(0)
          nil_A :: [] -(0)-> A(1, 0)
          nil_A :: [] -(0)-> A(0, 1)
        
* Step 2: Open MAYBE
    - Strict TRS:
        append(@l1,@l2) -> append#1(@l1,@l2)
        append#1(::(@x,@xs),@l2) -> ::(@x,append(@xs,@l2))
        append#1(nil(),@l2) -> @l2
        appendAll(@l) -> appendAll#1(@l)
        appendAll#1(::(@l1,@ls)) -> append(@l1,appendAll(@ls))
        appendAll#1(nil()) -> nil()
        appendAll2(@l) -> appendAll2#1(@l)
        appendAll2#1(::(@l1,@ls)) -> append(appendAll(@l1),appendAll2(@ls))
        appendAll2#1(nil()) -> nil()
        appendAll3(@l) -> appendAll3#1(@l)
        appendAll3#1(::(@l1,@ls)) -> append(appendAll2(@l1),appendAll3(@ls))
        appendAll3#1(nil()) -> nil()
    - Signature:
        {append/2,append#1/2,appendAll/1,appendAll#1/1,appendAll2/1,appendAll2#1/1,appendAll3/1
        ,appendAll3#1/1} / {::/2,nil/0}
    - Obligation:
        innermost runtime complexity wrt. defined symbols {append,append#1,appendAll,appendAll#1,appendAll2
        ,appendAll2#1,appendAll3,appendAll3#1} and constructors {::,nil}
Following problems could not be solved:
  - Strict TRS:
      append(@l1,@l2) -> append#1(@l1,@l2)
      append#1(::(@x,@xs),@l2) -> ::(@x,append(@xs,@l2))
      append#1(nil(),@l2) -> @l2
      appendAll(@l) -> appendAll#1(@l)
      appendAll#1(::(@l1,@ls)) -> append(@l1,appendAll(@ls))
      appendAll#1(nil()) -> nil()
      appendAll2(@l) -> appendAll2#1(@l)
      appendAll2#1(::(@l1,@ls)) -> append(appendAll(@l1),appendAll2(@ls))
      appendAll2#1(nil()) -> nil()
      appendAll3(@l) -> appendAll3#1(@l)
      appendAll3#1(::(@l1,@ls)) -> append(appendAll2(@l1),appendAll3(@ls))
      appendAll3#1(nil()) -> nil()
  - Signature:
      {append/2,append#1/2,appendAll/1,appendAll#1/1,appendAll2/1,appendAll2#1/1,appendAll3/1
      ,appendAll3#1/1} / {::/2,nil/0}
  - Obligation:
      innermost runtime complexity wrt. defined symbols {append,append#1,appendAll,appendAll#1,appendAll2
      ,appendAll2#1,appendAll3,appendAll3#1} and constructors {::,nil}
WORST_CASE(?,O(n^2))