MAYBE
* Step 1: InnermostRuleRemoval MAYBE
    + Considered Problem:
        - Strict TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            U61(tt(),L,N) -> U62(isNat(activate(N)),activate(L))
            U62(tt(),L) -> s(length(activate(L)))
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            length(cons(N,L)) -> U61(isNatList(activate(L)),activate(L),N)
            length(nil()) -> 0()
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0} / {n__0/0,n__cons/2,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0,U11,U21,U31,U41,U42,U51,U52,U61,U62,activate,cons,isNat
            ,isNatIList,isNatList,length,nil,s,zeros} and constructors {n__0,n__cons,n__length,n__nil,n__s,n__zeros,tt}
    + Applied Processor:
        InnermostRuleRemoval
    + Details:
        Arguments of following rules are not normal-forms.
          length(cons(N,L)) -> U61(isNatList(activate(L)),activate(L),N)
          length(nil()) -> 0()
        All above mentioned rules can be savely removed.
* Step 2: DependencyPairs MAYBE
    + Considered Problem:
        - Strict TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            U61(tt(),L,N) -> U62(isNat(activate(N)),activate(L))
            U62(tt(),L) -> s(length(activate(L)))
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0} / {n__0/0,n__cons/2,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0,U11,U21,U31,U41,U42,U51,U52,U61,U62,activate,cons,isNat
            ,isNatIList,isNatList,length,nil,s,zeros} and constructors {n__0,n__cons,n__length,n__nil,n__s,n__zeros,tt}
    + Applied Processor:
        DependencyPairs {dpKind_ = DT}
    + Details:
        We add the following dependency tuples:
        
        Strict DPs
          0#() -> c_1()
          U11#(tt()) -> c_2()
          U21#(tt()) -> c_3()
          U31#(tt()) -> c_4()
          U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
          U42#(tt()) -> c_6()
          U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
          U52#(tt()) -> c_8()
          U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
          U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          activate#(X) -> c_11()
          activate#(n__0()) -> c_12(0#())
          activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          activate#(n__length(X)) -> c_14(length#(X))
          activate#(n__nil()) -> c_15(nil#())
          activate#(n__s(X)) -> c_16(s#(X))
          activate#(n__zeros()) -> c_17(zeros#())
          cons#(X1,X2) -> c_18()
          isNat#(n__0()) -> c_19()
          isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
          isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
          isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
          isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                             ,isNat#(activate(V1))
                                             ,activate#(V1)
                                             ,activate#(V2))
          isNatIList#(n__zeros()) -> c_24()
          isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                            ,isNat#(activate(V1))
                                            ,activate#(V1)
                                            ,activate#(V2))
          isNatList#(n__nil()) -> c_26()
          length#(X) -> c_27()
          nil#() -> c_28()
          s#(X) -> c_29()
          zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          zeros#() -> c_31()
        Weak DPs
          
        
        and mark the set of starting terms.
* Step 3: UsableRules MAYBE
    + Considered Problem:
        - Strict DPs:
            0#() -> c_1()
            U11#(tt()) -> c_2()
            U21#(tt()) -> c_3()
            U31#(tt()) -> c_4()
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U42#(tt()) -> c_6()
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U52#(tt()) -> c_8()
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
            activate#(X) -> c_11()
            activate#(n__0()) -> c_12(0#())
            activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
            activate#(n__length(X)) -> c_14(length#(X))
            activate#(n__nil()) -> c_15(nil#())
            activate#(n__s(X)) -> c_16(s#(X))
            activate#(n__zeros()) -> c_17(zeros#())
            cons#(X1,X2) -> c_18()
            isNat#(n__0()) -> c_19()
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatIList#(n__zeros()) -> c_24()
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
            isNatList#(n__nil()) -> c_26()
            length#(X) -> c_27()
            nil#() -> c_28()
            s#(X) -> c_29()
            zeros#() -> c_30(cons#(0(),n__zeros()),0#())
            zeros#() -> c_31()
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            U61(tt(),L,N) -> U62(isNat(activate(N)),activate(L))
            U62(tt(),L) -> s(length(activate(L)))
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        UsableRules
    + Details:
        We replace rewrite rules by usable rules:
          0() -> n__0()
          U11(tt()) -> tt()
          U21(tt()) -> tt()
          U31(tt()) -> tt()
          U41(tt(),V2) -> U42(isNatIList(activate(V2)))
          U42(tt()) -> tt()
          U51(tt(),V2) -> U52(isNatList(activate(V2)))
          U52(tt()) -> tt()
          activate(X) -> X
          activate(n__0()) -> 0()
          activate(n__cons(X1,X2)) -> cons(X1,X2)
          activate(n__length(X)) -> length(X)
          activate(n__nil()) -> nil()
          activate(n__s(X)) -> s(X)
          activate(n__zeros()) -> zeros()
          cons(X1,X2) -> n__cons(X1,X2)
          isNat(n__0()) -> tt()
          isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
          isNat(n__s(V1)) -> U21(isNat(activate(V1)))
          isNatIList(V) -> U31(isNatList(activate(V)))
          isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
          isNatIList(n__zeros()) -> tt()
          isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
          isNatList(n__nil()) -> tt()
          length(X) -> n__length(X)
          nil() -> n__nil()
          s(X) -> n__s(X)
          zeros() -> cons(0(),n__zeros())
          zeros() -> n__zeros()
          0#() -> c_1()
          U11#(tt()) -> c_2()
          U21#(tt()) -> c_3()
          U31#(tt()) -> c_4()
          U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
          U42#(tt()) -> c_6()
          U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
          U52#(tt()) -> c_8()
          U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
          U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          activate#(X) -> c_11()
          activate#(n__0()) -> c_12(0#())
          activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          activate#(n__length(X)) -> c_14(length#(X))
          activate#(n__nil()) -> c_15(nil#())
          activate#(n__s(X)) -> c_16(s#(X))
          activate#(n__zeros()) -> c_17(zeros#())
          cons#(X1,X2) -> c_18()
          isNat#(n__0()) -> c_19()
          isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
          isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
          isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
          isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                             ,isNat#(activate(V1))
                                             ,activate#(V1)
                                             ,activate#(V2))
          isNatIList#(n__zeros()) -> c_24()
          isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                            ,isNat#(activate(V1))
                                            ,activate#(V1)
                                            ,activate#(V2))
          isNatList#(n__nil()) -> c_26()
          length#(X) -> c_27()
          nil#() -> c_28()
          s#(X) -> c_29()
          zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          zeros#() -> c_31()
* Step 4: PredecessorEstimation MAYBE
    + Considered Problem:
        - Strict DPs:
            0#() -> c_1()
            U11#(tt()) -> c_2()
            U21#(tt()) -> c_3()
            U31#(tt()) -> c_4()
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U42#(tt()) -> c_6()
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U52#(tt()) -> c_8()
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
            activate#(X) -> c_11()
            activate#(n__0()) -> c_12(0#())
            activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
            activate#(n__length(X)) -> c_14(length#(X))
            activate#(n__nil()) -> c_15(nil#())
            activate#(n__s(X)) -> c_16(s#(X))
            activate#(n__zeros()) -> c_17(zeros#())
            cons#(X1,X2) -> c_18()
            isNat#(n__0()) -> c_19()
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatIList#(n__zeros()) -> c_24()
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
            isNatList#(n__nil()) -> c_26()
            length#(X) -> c_27()
            nil#() -> c_28()
            s#(X) -> c_29()
            zeros#() -> c_30(cons#(0(),n__zeros()),0#())
            zeros#() -> c_31()
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        PredecessorEstimation {onSelection = all simple predecessor estimation selector}
    + Details:
        We estimate the number of application of
          {1,2,3,4,6,8,11,18,19,24,26,27,28,29,31}
        by application of
          Pre({1,2,3,4,6,8,11,18,19,24,26,27,28,29,31}) = {5,7,9,10,12,13,14,15,16,17,20,21,22,23,25,30}.
        Here rules are labelled as follows:
          1: 0#() -> c_1()
          2: U11#(tt()) -> c_2()
          3: U21#(tt()) -> c_3()
          4: U31#(tt()) -> c_4()
          5: U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
          6: U42#(tt()) -> c_6()
          7: U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
          8: U52#(tt()) -> c_8()
          9: U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
          10: U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          11: activate#(X) -> c_11()
          12: activate#(n__0()) -> c_12(0#())
          13: activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          14: activate#(n__length(X)) -> c_14(length#(X))
          15: activate#(n__nil()) -> c_15(nil#())
          16: activate#(n__s(X)) -> c_16(s#(X))
          17: activate#(n__zeros()) -> c_17(zeros#())
          18: cons#(X1,X2) -> c_18()
          19: isNat#(n__0()) -> c_19()
          20: isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
          21: isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
          22: isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
          23: isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                 ,isNat#(activate(V1))
                                                 ,activate#(V1)
                                                 ,activate#(V2))
          24: isNatIList#(n__zeros()) -> c_24()
          25: isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
          26: isNatList#(n__nil()) -> c_26()
          27: length#(X) -> c_27()
          28: nil#() -> c_28()
          29: s#(X) -> c_29()
          30: zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          31: zeros#() -> c_31()
* Step 5: PredecessorEstimation MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
            activate#(n__0()) -> c_12(0#())
            activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
            activate#(n__length(X)) -> c_14(length#(X))
            activate#(n__nil()) -> c_15(nil#())
            activate#(n__s(X)) -> c_16(s#(X))
            activate#(n__zeros()) -> c_17(zeros#())
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
            zeros#() -> c_30(cons#(0(),n__zeros()),0#())
        - Weak DPs:
            0#() -> c_1()
            U11#(tt()) -> c_2()
            U21#(tt()) -> c_3()
            U31#(tt()) -> c_4()
            U42#(tt()) -> c_6()
            U52#(tt()) -> c_8()
            activate#(X) -> c_11()
            cons#(X1,X2) -> c_18()
            isNat#(n__0()) -> c_19()
            isNatIList#(n__zeros()) -> c_24()
            isNatList#(n__nil()) -> c_26()
            length#(X) -> c_27()
            nil#() -> c_28()
            s#(X) -> c_29()
            zeros#() -> c_31()
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        PredecessorEstimation {onSelection = all simple predecessor estimation selector}
    + Details:
        We estimate the number of application of
          {5,6,7,8,9,16}
        by application of
          Pre({5,6,7,8,9,16}) = {1,2,3,4,10,11,12,13,14,15}.
        Here rules are labelled as follows:
          1: U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
          2: U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
          3: U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
          4: U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          5: activate#(n__0()) -> c_12(0#())
          6: activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          7: activate#(n__length(X)) -> c_14(length#(X))
          8: activate#(n__nil()) -> c_15(nil#())
          9: activate#(n__s(X)) -> c_16(s#(X))
          10: activate#(n__zeros()) -> c_17(zeros#())
          11: isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
          12: isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
          13: isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
          14: isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                 ,isNat#(activate(V1))
                                                 ,activate#(V1)
                                                 ,activate#(V2))
          15: isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
          16: zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          17: 0#() -> c_1()
          18: U11#(tt()) -> c_2()
          19: U21#(tt()) -> c_3()
          20: U31#(tt()) -> c_4()
          21: U42#(tt()) -> c_6()
          22: U52#(tt()) -> c_8()
          23: activate#(X) -> c_11()
          24: cons#(X1,X2) -> c_18()
          25: isNat#(n__0()) -> c_19()
          26: isNatIList#(n__zeros()) -> c_24()
          27: isNatList#(n__nil()) -> c_26()
          28: length#(X) -> c_27()
          29: nil#() -> c_28()
          30: s#(X) -> c_29()
          31: zeros#() -> c_31()
* Step 6: PredecessorEstimation MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
            activate#(n__zeros()) -> c_17(zeros#())
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
        - Weak DPs:
            0#() -> c_1()
            U11#(tt()) -> c_2()
            U21#(tt()) -> c_3()
            U31#(tt()) -> c_4()
            U42#(tt()) -> c_6()
            U52#(tt()) -> c_8()
            activate#(X) -> c_11()
            activate#(n__0()) -> c_12(0#())
            activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
            activate#(n__length(X)) -> c_14(length#(X))
            activate#(n__nil()) -> c_15(nil#())
            activate#(n__s(X)) -> c_16(s#(X))
            cons#(X1,X2) -> c_18()
            isNat#(n__0()) -> c_19()
            isNatIList#(n__zeros()) -> c_24()
            isNatList#(n__nil()) -> c_26()
            length#(X) -> c_27()
            nil#() -> c_28()
            s#(X) -> c_29()
            zeros#() -> c_30(cons#(0(),n__zeros()),0#())
            zeros#() -> c_31()
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        PredecessorEstimation {onSelection = all simple predecessor estimation selector}
    + Details:
        We estimate the number of application of
          {5}
        by application of
          Pre({5}) = {1,2,3,4,6,7,8,9,10}.
        Here rules are labelled as follows:
          1: U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
          2: U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
          3: U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
          4: U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          5: activate#(n__zeros()) -> c_17(zeros#())
          6: isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
          7: isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
          8: isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
          9: isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
          10: isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
          11: 0#() -> c_1()
          12: U11#(tt()) -> c_2()
          13: U21#(tt()) -> c_3()
          14: U31#(tt()) -> c_4()
          15: U42#(tt()) -> c_6()
          16: U52#(tt()) -> c_8()
          17: activate#(X) -> c_11()
          18: activate#(n__0()) -> c_12(0#())
          19: activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          20: activate#(n__length(X)) -> c_14(length#(X))
          21: activate#(n__nil()) -> c_15(nil#())
          22: activate#(n__s(X)) -> c_16(s#(X))
          23: cons#(X1,X2) -> c_18()
          24: isNat#(n__0()) -> c_19()
          25: isNatIList#(n__zeros()) -> c_24()
          26: isNatList#(n__nil()) -> c_26()
          27: length#(X) -> c_27()
          28: nil#() -> c_28()
          29: s#(X) -> c_29()
          30: zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          31: zeros#() -> c_31()
* Step 7: PredecessorEstimation MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
        - Weak DPs:
            0#() -> c_1()
            U11#(tt()) -> c_2()
            U21#(tt()) -> c_3()
            U31#(tt()) -> c_4()
            U42#(tt()) -> c_6()
            U52#(tt()) -> c_8()
            activate#(X) -> c_11()
            activate#(n__0()) -> c_12(0#())
            activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
            activate#(n__length(X)) -> c_14(length#(X))
            activate#(n__nil()) -> c_15(nil#())
            activate#(n__s(X)) -> c_16(s#(X))
            activate#(n__zeros()) -> c_17(zeros#())
            cons#(X1,X2) -> c_18()
            isNat#(n__0()) -> c_19()
            isNatIList#(n__zeros()) -> c_24()
            isNatList#(n__nil()) -> c_26()
            length#(X) -> c_27()
            nil#() -> c_28()
            s#(X) -> c_29()
            zeros#() -> c_30(cons#(0(),n__zeros()),0#())
            zeros#() -> c_31()
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        PredecessorEstimation {onSelection = all simple predecessor estimation selector}
    + Details:
        We estimate the number of application of
          {4}
        by application of
          Pre({4}) = {3}.
        Here rules are labelled as follows:
          1: U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
          2: U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
          3: U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
          4: U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          5: isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
          6: isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
          7: isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
          8: isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
          9: isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
          10: 0#() -> c_1()
          11: U11#(tt()) -> c_2()
          12: U21#(tt()) -> c_3()
          13: U31#(tt()) -> c_4()
          14: U42#(tt()) -> c_6()
          15: U52#(tt()) -> c_8()
          16: activate#(X) -> c_11()
          17: activate#(n__0()) -> c_12(0#())
          18: activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          19: activate#(n__length(X)) -> c_14(length#(X))
          20: activate#(n__nil()) -> c_15(nil#())
          21: activate#(n__s(X)) -> c_16(s#(X))
          22: activate#(n__zeros()) -> c_17(zeros#())
          23: cons#(X1,X2) -> c_18()
          24: isNat#(n__0()) -> c_19()
          25: isNatIList#(n__zeros()) -> c_24()
          26: isNatList#(n__nil()) -> c_26()
          27: length#(X) -> c_27()
          28: nil#() -> c_28()
          29: s#(X) -> c_29()
          30: zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          31: zeros#() -> c_31()
* Step 8: RemoveWeakSuffixes MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
        - Weak DPs:
            0#() -> c_1()
            U11#(tt()) -> c_2()
            U21#(tt()) -> c_3()
            U31#(tt()) -> c_4()
            U42#(tt()) -> c_6()
            U52#(tt()) -> c_8()
            U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
            activate#(X) -> c_11()
            activate#(n__0()) -> c_12(0#())
            activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
            activate#(n__length(X)) -> c_14(length#(X))
            activate#(n__nil()) -> c_15(nil#())
            activate#(n__s(X)) -> c_16(s#(X))
            activate#(n__zeros()) -> c_17(zeros#())
            cons#(X1,X2) -> c_18()
            isNat#(n__0()) -> c_19()
            isNatIList#(n__zeros()) -> c_24()
            isNatList#(n__nil()) -> c_26()
            length#(X) -> c_27()
            nil#() -> c_28()
            s#(X) -> c_29()
            zeros#() -> c_30(cons#(0(),n__zeros()),0#())
            zeros#() -> c_31()
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        RemoveWeakSuffixes
    + Details:
        Consider the dependency graph
          1:S:U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                      ,isNat#(activate(V1))
                                                      ,activate#(V1)
                                                      ,activate#(V2)):7
             -->_2 isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V)):6
             -->_2 isNatIList#(n__zeros()) -> c_24():25
             -->_3 activate#(X) -> c_11():16
             -->_1 U42#(tt()) -> c_6():13
          
          2:S:U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                     ,isNat#(activate(V1))
                                                     ,activate#(V1)
                                                     ,activate#(V2)):8
             -->_2 isNatList#(n__nil()) -> c_26():26
             -->_3 activate#(X) -> c_11():16
             -->_1 U52#(tt()) -> c_8():14
          
          3:S:U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L))
                                   ,isNat#(activate(N))
                                   ,activate#(N)
                                   ,activate#(L))
             -->_4 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_4 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_4 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_4 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_4 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_4 activate#(n__0()) -> c_12(0#()):17
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_1 U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L)):15
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
             -->_2 isNat#(n__0()) -> c_19():24
             -->_4 activate#(X) -> c_11():16
             -->_3 activate#(X) -> c_11():16
          
          4:S:isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                     ,isNat#(activate(V1))
                                                     ,activate#(V1)
                                                     ,activate#(V2)):8
             -->_2 isNatList#(n__nil()) -> c_26():26
             -->_3 activate#(X) -> c_11():16
             -->_1 U11#(tt()) -> c_2():10
          
          5:S:isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNat#(n__0()) -> c_19():24
             -->_3 activate#(X) -> c_11():16
             -->_1 U21#(tt()) -> c_3():11
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
          
          6:S:isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                     ,isNat#(activate(V1))
                                                     ,activate#(V1)
                                                     ,activate#(V2)):8
             -->_2 isNatList#(n__nil()) -> c_26():26
             -->_3 activate#(X) -> c_11():16
             -->_1 U31#(tt()) -> c_4():12
          
          7:S:isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                 ,isNat#(activate(V1))
                                                 ,activate#(V1)
                                                 ,activate#(V2))
             -->_4 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_4 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_4 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_4 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_4 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_4 activate#(n__0()) -> c_12(0#()):17
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNat#(n__0()) -> c_19():24
             -->_4 activate#(X) -> c_11():16
             -->_3 activate#(X) -> c_11():16
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
             -->_1 U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2)):1
          
          8:S:isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
             -->_4 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_4 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_4 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_4 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_4 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_4 activate#(n__0()) -> c_12(0#()):17
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_2 isNat#(n__0()) -> c_19():24
             -->_4 activate#(X) -> c_11():16
             -->_3 activate#(X) -> c_11():16
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
             -->_1 U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2)):2
          
          9:W:0#() -> c_1()
             
          
          10:W:U11#(tt()) -> c_2()
             
          
          11:W:U21#(tt()) -> c_3()
             
          
          12:W:U31#(tt()) -> c_4()
             
          
          13:W:U42#(tt()) -> c_6()
             
          
          14:W:U52#(tt()) -> c_8()
             
          
          15:W:U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
             -->_3 activate#(n__zeros()) -> c_17(zeros#()):22
             -->_3 activate#(n__s(X)) -> c_16(s#(X)):21
             -->_3 activate#(n__nil()) -> c_15(nil#()):20
             -->_3 activate#(n__length(X)) -> c_14(length#(X)):19
             -->_3 activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2)):18
             -->_3 activate#(n__0()) -> c_12(0#()):17
             -->_1 s#(X) -> c_29():29
             -->_2 length#(X) -> c_27():27
             -->_3 activate#(X) -> c_11():16
          
          16:W:activate#(X) -> c_11()
             
          
          17:W:activate#(n__0()) -> c_12(0#())
             -->_1 0#() -> c_1():9
          
          18:W:activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
             -->_1 cons#(X1,X2) -> c_18():23
          
          19:W:activate#(n__length(X)) -> c_14(length#(X))
             -->_1 length#(X) -> c_27():27
          
          20:W:activate#(n__nil()) -> c_15(nil#())
             -->_1 nil#() -> c_28():28
          
          21:W:activate#(n__s(X)) -> c_16(s#(X))
             -->_1 s#(X) -> c_29():29
          
          22:W:activate#(n__zeros()) -> c_17(zeros#())
             -->_1 zeros#() -> c_30(cons#(0(),n__zeros()),0#()):30
             -->_1 zeros#() -> c_31():31
          
          23:W:cons#(X1,X2) -> c_18()
             
          
          24:W:isNat#(n__0()) -> c_19()
             
          
          25:W:isNatIList#(n__zeros()) -> c_24()
             
          
          26:W:isNatList#(n__nil()) -> c_26()
             
          
          27:W:length#(X) -> c_27()
             
          
          28:W:nil#() -> c_28()
             
          
          29:W:s#(X) -> c_29()
             
          
          30:W:zeros#() -> c_30(cons#(0(),n__zeros()),0#())
             -->_1 cons#(X1,X2) -> c_18():23
             -->_2 0#() -> c_1():9
          
          31:W:zeros#() -> c_31()
             
          
        The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed.
          15: U62#(tt(),L) -> c_10(s#(length(activate(L))),length#(activate(L)),activate#(L))
          13: U42#(tt()) -> c_6()
          25: isNatIList#(n__zeros()) -> c_24()
          12: U31#(tt()) -> c_4()
          10: U11#(tt()) -> c_2()
          14: U52#(tt()) -> c_8()
          26: isNatList#(n__nil()) -> c_26()
          11: U21#(tt()) -> c_3()
          16: activate#(X) -> c_11()
          24: isNat#(n__0()) -> c_19()
          17: activate#(n__0()) -> c_12(0#())
          18: activate#(n__cons(X1,X2)) -> c_13(cons#(X1,X2))
          19: activate#(n__length(X)) -> c_14(length#(X))
          27: length#(X) -> c_27()
          20: activate#(n__nil()) -> c_15(nil#())
          28: nil#() -> c_28()
          21: activate#(n__s(X)) -> c_16(s#(X))
          29: s#(X) -> c_29()
          22: activate#(n__zeros()) -> c_17(zeros#())
          31: zeros#() -> c_31()
          30: zeros#() -> c_30(cons#(0(),n__zeros()),0#())
          9: 0#() -> c_1()
          23: cons#(X1,X2) -> c_18()
* Step 9: SimplifyRHS MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
            U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
            U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L)),isNat#(activate(N)),activate#(N),activate#(L))
            isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
            isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
            isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                               ,isNat#(activate(V1))
                                               ,activate#(V1)
                                               ,activate#(V2))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                              ,isNat#(activate(V1))
                                              ,activate#(V1)
                                              ,activate#(V2))
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/3,c_6/0,c_7/3,c_8/0,c_9/4,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/3,c_21/3,c_22/3,c_23/4,c_24/0,c_25/4
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        SimplifyRHS
    + Details:
        Consider the dependency graph
          1:S:U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2))
             -->_2 isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                      ,isNat#(activate(V1))
                                                      ,activate#(V1)
                                                      ,activate#(V2)):7
             -->_2 isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V)):6
          
          2:S:U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2))
             -->_2 isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                     ,isNat#(activate(V1))
                                                     ,activate#(V1)
                                                     ,activate#(V2)):8
          
          3:S:U61#(tt(),L,N) -> c_9(U62#(isNat(activate(N)),activate(L))
                                   ,isNat#(activate(N))
                                   ,activate#(N)
                                   ,activate#(L))
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
          
          4:S:isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1))
             -->_2 isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                     ,isNat#(activate(V1))
                                                     ,activate#(V1)
                                                     ,activate#(V2)):8
          
          5:S:isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1))
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
          
          6:S:isNatIList#(V) -> c_22(U31#(isNatList(activate(V))),isNatList#(activate(V)),activate#(V))
             -->_2 isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                     ,isNat#(activate(V1))
                                                     ,activate#(V1)
                                                     ,activate#(V2)):8
          
          7:S:isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2))
                                                 ,isNat#(activate(V1))
                                                 ,activate#(V1)
                                                 ,activate#(V2))
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
             -->_1 U41#(tt(),V2) -> c_5(U42#(isNatIList(activate(V2))),isNatIList#(activate(V2)),activate#(V2)):1
          
          8:S:isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2))
                                                ,isNat#(activate(V1))
                                                ,activate#(V1)
                                                ,activate#(V2))
             -->_2 isNat#(n__s(V1)) -> c_21(U21#(isNat(activate(V1))),isNat#(activate(V1)),activate#(V1)):5
             -->_2 isNat#(n__length(V1)) -> c_20(U11#(isNatList(activate(V1))),isNatList#(activate(V1)),activate#(V1)):4
             -->_1 U51#(tt(),V2) -> c_7(U52#(isNatList(activate(V2))),isNatList#(activate(V2)),activate#(V2)):2
          
        Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified:
          U41#(tt(),V2) -> c_5(isNatIList#(activate(V2)))
          U51#(tt(),V2) -> c_7(isNatList#(activate(V2)))
          U61#(tt(),L,N) -> c_9(isNat#(activate(N)))
          isNat#(n__length(V1)) -> c_20(isNatList#(activate(V1)))
          isNat#(n__s(V1)) -> c_21(isNat#(activate(V1)))
          isNatIList#(V) -> c_22(isNatList#(activate(V)))
          isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
          isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
* Step 10: UsableRules MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(isNatIList#(activate(V2)))
            U51#(tt(),V2) -> c_7(isNatList#(activate(V2)))
            U61#(tt(),L,N) -> c_9(isNat#(activate(N)))
            isNat#(n__length(V1)) -> c_20(isNatList#(activate(V1)))
            isNat#(n__s(V1)) -> c_21(isNat#(activate(V1)))
            isNatIList#(V) -> c_22(isNatList#(activate(V)))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U31(tt()) -> tt()
            U41(tt(),V2) -> U42(isNatIList(activate(V2)))
            U42(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatIList(V) -> U31(isNatList(activate(V)))
            isNatIList(n__cons(V1,V2)) -> U41(isNat(activate(V1)),activate(V2))
            isNatIList(n__zeros()) -> tt()
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/1,c_6/0,c_7/1,c_8/0,c_9/1,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/1,c_21/1,c_22/1,c_23/2,c_24/0,c_25/2
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        UsableRules
    + Details:
        We replace rewrite rules by usable rules:
          0() -> n__0()
          U11(tt()) -> tt()
          U21(tt()) -> tt()
          U51(tt(),V2) -> U52(isNatList(activate(V2)))
          U52(tt()) -> tt()
          activate(X) -> X
          activate(n__0()) -> 0()
          activate(n__cons(X1,X2)) -> cons(X1,X2)
          activate(n__length(X)) -> length(X)
          activate(n__nil()) -> nil()
          activate(n__s(X)) -> s(X)
          activate(n__zeros()) -> zeros()
          cons(X1,X2) -> n__cons(X1,X2)
          isNat(n__0()) -> tt()
          isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
          isNat(n__s(V1)) -> U21(isNat(activate(V1)))
          isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
          isNatList(n__nil()) -> tt()
          length(X) -> n__length(X)
          nil() -> n__nil()
          s(X) -> n__s(X)
          zeros() -> cons(0(),n__zeros())
          zeros() -> n__zeros()
          U41#(tt(),V2) -> c_5(isNatIList#(activate(V2)))
          U51#(tt(),V2) -> c_7(isNatList#(activate(V2)))
          U61#(tt(),L,N) -> c_9(isNat#(activate(N)))
          isNat#(n__length(V1)) -> c_20(isNatList#(activate(V1)))
          isNat#(n__s(V1)) -> c_21(isNat#(activate(V1)))
          isNatIList#(V) -> c_22(isNatList#(activate(V)))
          isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
          isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
* Step 11: NaturalMI MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(isNatIList#(activate(V2)))
            U51#(tt(),V2) -> c_7(isNatList#(activate(V2)))
            U61#(tt(),L,N) -> c_9(isNat#(activate(N)))
            isNat#(n__length(V1)) -> c_20(isNatList#(activate(V1)))
            isNat#(n__s(V1)) -> c_21(isNat#(activate(V1)))
            isNatIList#(V) -> c_22(isNatList#(activate(V)))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/1,c_6/0,c_7/1,c_8/0,c_9/1,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/1,c_21/1,c_22/1,c_23/2,c_24/0,c_25/2
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        NaturalMI {miDimension = 1, miDegree = 0, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a matrix interpretation of kind constructor based matrix interpretation (containing no more than 0 non-zero interpretation-entries in the diagonal of the component-wise maxima):
        The following argument positions are considered usable:
          uargs(c_5) = {1},
          uargs(c_7) = {1},
          uargs(c_9) = {1},
          uargs(c_20) = {1},
          uargs(c_21) = {1},
          uargs(c_22) = {1},
          uargs(c_23) = {1,2},
          uargs(c_25) = {1,2}
        
        Following symbols are considered usable:
          {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#,cons#,isNat#,isNatIList#,isNatList#,length#
          ,nil#,s#,zeros#}
        TcT has computed the following interpretation:
                    p(0) = [0]                  
                  p(U11) = [0]                  
                  p(U21) = [0]                  
                  p(U31) = [0]                  
                  p(U41) = [0]                  
                  p(U42) = [0]                  
                  p(U51) = [0]                  
                  p(U52) = [0]                  
                  p(U61) = [0]                  
                  p(U62) = [0]                  
             p(activate) = [4]                  
                 p(cons) = [0]                  
                p(isNat) = [4]                  
           p(isNatIList) = [0]                  
            p(isNatList) = [0]                  
               p(length) = [0]                  
                 p(n__0) = [0]                  
              p(n__cons) = [0]                  
            p(n__length) = [0]                  
               p(n__nil) = [0]                  
                 p(n__s) = [1]                  
             p(n__zeros) = [4]                  
                  p(nil) = [4]                  
                    p(s) = [1]                  
                   p(tt) = [0]                  
                p(zeros) = [1]                  
                   p(0#) = [4]                  
                 p(U11#) = [1]                  
                 p(U21#) = [1]                  
                 p(U31#) = [1]                  
                 p(U41#) = [0]                  
                 p(U42#) = [2] x1 + [1]         
                 p(U51#) = [0]                  
                 p(U52#) = [1]                  
                 p(U61#) = [1] x2 + [1] x3 + [6]
                 p(U62#) = [2] x2 + [1]         
            p(activate#) = [0]                  
                p(cons#) = [0]                  
               p(isNat#) = [0]                  
          p(isNatIList#) = [0]                  
           p(isNatList#) = [0]                  
              p(length#) = [0]                  
                 p(nil#) = [0]                  
                   p(s#) = [2] x1 + [4]         
               p(zeros#) = [0]                  
                  p(c_1) = [1]                  
                  p(c_2) = [1]                  
                  p(c_3) = [2]                  
                  p(c_4) = [0]                  
                  p(c_5) = [4] x1 + [0]         
                  p(c_6) = [1]                  
                  p(c_7) = [4] x1 + [0]         
                  p(c_8) = [1]                  
                  p(c_9) = [2] x1 + [2]         
                 p(c_10) = [4] x3 + [1]         
                 p(c_11) = [1]                  
                 p(c_12) = [0]                  
                 p(c_13) = [1] x1 + [2]         
                 p(c_14) = [1]                  
                 p(c_15) = [0]                  
                 p(c_16) = [2] x1 + [0]         
                 p(c_17) = [1]                  
                 p(c_18) = [0]                  
                 p(c_19) = [1]                  
                 p(c_20) = [1] x1 + [0]         
                 p(c_21) = [1] x1 + [0]         
                 p(c_22) = [1] x1 + [0]         
                 p(c_23) = [4] x1 + [1] x2 + [0]
                 p(c_24) = [0]                  
                 p(c_25) = [4] x1 + [2] x2 + [0]
                 p(c_26) = [1]                  
                 p(c_27) = [1]                  
                 p(c_28) = [1]                  
                 p(c_29) = [0]                  
                 p(c_30) = [1] x2 + [0]         
                 p(c_31) = [1]                  
        
        Following rules are strictly oriented:
        U61#(tt(),L,N) = [1] L + [1] N + [6]     
                       > [2]                     
                       = c_9(isNat#(activate(N)))
        
        
        Following rules are (at-least) weakly oriented:
                      U41#(tt(),V2) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_5(isNatIList#(activate(V2)))                                   
        
                      U51#(tt(),V2) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_7(isNatList#(activate(V2)))                                    
        
              isNat#(n__length(V1)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_20(isNatList#(activate(V1)))                                   
        
                   isNat#(n__s(V1)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_21(isNat#(activate(V1)))                                       
        
                     isNatIList#(V) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_22(isNatList#(activate(V)))                                    
        
        isNatIList#(n__cons(V1,V2)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        
         isNatList#(n__cons(V1,V2)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        
* Step 12: NaturalMI MAYBE
    + Considered Problem:
        - Strict DPs:
            U41#(tt(),V2) -> c_5(isNatIList#(activate(V2)))
            U51#(tt(),V2) -> c_7(isNatList#(activate(V2)))
            isNat#(n__length(V1)) -> c_20(isNatList#(activate(V1)))
            isNat#(n__s(V1)) -> c_21(isNat#(activate(V1)))
            isNatIList#(V) -> c_22(isNatList#(activate(V)))
            isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
            isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        - Weak DPs:
            U61#(tt(),L,N) -> c_9(isNat#(activate(N)))
        - Weak TRS:
            0() -> n__0()
            U11(tt()) -> tt()
            U21(tt()) -> tt()
            U51(tt(),V2) -> U52(isNatList(activate(V2)))
            U52(tt()) -> tt()
            activate(X) -> X
            activate(n__0()) -> 0()
            activate(n__cons(X1,X2)) -> cons(X1,X2)
            activate(n__length(X)) -> length(X)
            activate(n__nil()) -> nil()
            activate(n__s(X)) -> s(X)
            activate(n__zeros()) -> zeros()
            cons(X1,X2) -> n__cons(X1,X2)
            isNat(n__0()) -> tt()
            isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
            isNat(n__s(V1)) -> U21(isNat(activate(V1)))
            isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
            isNatList(n__nil()) -> tt()
            length(X) -> n__length(X)
            nil() -> n__nil()
            s(X) -> n__s(X)
            zeros() -> cons(0(),n__zeros())
            zeros() -> n__zeros()
        - Signature:
            {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
            ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
            ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
            ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/1,c_6/0,c_7/1,c_8/0,c_9/1,c_10/3
            ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/1,c_21/1,c_22/1,c_23/2,c_24/0,c_25/2
            ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
            ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
            ,n__s,n__zeros,tt}
    + Applied Processor:
        NaturalMI {miDimension = 1, miDegree = 0, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just any strict-rules}
    + Details:
        We apply a matrix interpretation of kind constructor based matrix interpretation (containing no more than 0 non-zero interpretation-entries in the diagonal of the component-wise maxima):
        The following argument positions are considered usable:
          uargs(c_5) = {1},
          uargs(c_7) = {1},
          uargs(c_9) = {1},
          uargs(c_20) = {1},
          uargs(c_21) = {1},
          uargs(c_22) = {1},
          uargs(c_23) = {1,2},
          uargs(c_25) = {1,2}
        
        Following symbols are considered usable:
          {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#,cons#,isNat#,isNatIList#,isNatList#,length#
          ,nil#,s#,zeros#}
        TcT has computed the following interpretation:
                    p(0) = [0]                  
                  p(U11) = [4] x1 + [4]         
                  p(U21) = [0]                  
                  p(U31) = [4]                  
                  p(U41) = [1] x2 + [2]         
                  p(U42) = [1]                  
                  p(U51) = [0]                  
                  p(U52) = [1] x1 + [0]         
                  p(U61) = [0]                  
                  p(U62) = [4] x1 + [1]         
             p(activate) = [3] x1 + [0]         
                 p(cons) = [2] x1 + [1] x2 + [5]
                p(isNat) = [4] x1 + [4]         
           p(isNatIList) = [2] x1 + [1]         
            p(isNatList) = [1] x1 + [2]         
               p(length) = [1] x1 + [1]         
                 p(n__0) = [0]                  
              p(n__cons) = [0]                  
            p(n__length) = [1]                  
               p(n__nil) = [2]                  
                 p(n__s) = [1]                  
             p(n__zeros) = [1]                  
                  p(nil) = [4]                  
                    p(s) = [0]                  
                   p(tt) = [0]                  
                p(zeros) = [0]                  
                   p(0#) = [4]                  
                 p(U11#) = [2] x1 + [0]         
                 p(U21#) = [1] x1 + [1]         
                 p(U31#) = [2]                  
                 p(U41#) = [4]                  
                 p(U42#) = [1] x1 + [4]         
                 p(U51#) = [0]                  
                 p(U52#) = [1] x1 + [1]         
                 p(U61#) = [1] x1 + [4] x3 + [4]
                 p(U62#) = [1] x1 + [0]         
            p(activate#) = [0]                  
                p(cons#) = [4] x1 + [4]         
               p(isNat#) = [0]                  
          p(isNatIList#) = [4]                  
           p(isNatList#) = [0]                  
              p(length#) = [1]                  
                 p(nil#) = [0]                  
                   p(s#) = [2] x1 + [2]         
               p(zeros#) = [0]                  
                  p(c_1) = [2]                  
                  p(c_2) = [1]                  
                  p(c_3) = [2]                  
                  p(c_4) = [0]                  
                  p(c_5) = [1] x1 + [0]         
                  p(c_6) = [1]                  
                  p(c_7) = [1] x1 + [0]         
                  p(c_8) = [1]                  
                  p(c_9) = [1] x1 + [4]         
                 p(c_10) = [1] x1 + [1]         
                 p(c_11) = [0]                  
                 p(c_12) = [1] x1 + [1]         
                 p(c_13) = [1] x1 + [4]         
                 p(c_14) = [2]                  
                 p(c_15) = [0]                  
                 p(c_16) = [4] x1 + [0]         
                 p(c_17) = [4] x1 + [0]         
                 p(c_18) = [1]                  
                 p(c_19) = [1]                  
                 p(c_20) = [4] x1 + [0]         
                 p(c_21) = [4] x1 + [0]         
                 p(c_22) = [1] x1 + [3]         
                 p(c_23) = [1] x1 + [1] x2 + [0]
                 p(c_24) = [0]                  
                 p(c_25) = [4] x1 + [2] x2 + [0]
                 p(c_26) = [0]                  
                 p(c_27) = [2]                  
                 p(c_28) = [0]                  
                 p(c_29) = [0]                  
                 p(c_30) = [4] x1 + [4] x2 + [0]
                 p(c_31) = [1]                  
        
        Following rules are strictly oriented:
        isNatIList#(V) = [4]                          
                       > [3]                          
                       = c_22(isNatList#(activate(V)))
        
        
        Following rules are (at-least) weakly oriented:
                      U41#(tt(),V2) =  [4]                                                              
                                    >= [4]                                                              
                                    =  c_5(isNatIList#(activate(V2)))                                   
        
                      U51#(tt(),V2) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_7(isNatList#(activate(V2)))                                    
        
                     U61#(tt(),L,N) =  [4] N + [4]                                                      
                                    >= [4]                                                              
                                    =  c_9(isNat#(activate(N)))                                         
        
              isNat#(n__length(V1)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_20(isNatList#(activate(V1)))                                   
        
                   isNat#(n__s(V1)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_21(isNat#(activate(V1)))                                       
        
        isNatIList#(n__cons(V1,V2)) =  [4]                                                              
                                    >= [4]                                                              
                                    =  c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        
         isNatList#(n__cons(V1,V2)) =  [0]                                                              
                                    >= [0]                                                              
                                    =  c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
        
* Step 13: Failure MAYBE
  + Considered Problem:
      - Strict DPs:
          U41#(tt(),V2) -> c_5(isNatIList#(activate(V2)))
          U51#(tt(),V2) -> c_7(isNatList#(activate(V2)))
          isNat#(n__length(V1)) -> c_20(isNatList#(activate(V1)))
          isNat#(n__s(V1)) -> c_21(isNat#(activate(V1)))
          isNatIList#(n__cons(V1,V2)) -> c_23(U41#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
          isNatList#(n__cons(V1,V2)) -> c_25(U51#(isNat(activate(V1)),activate(V2)),isNat#(activate(V1)))
      - Weak DPs:
          U61#(tt(),L,N) -> c_9(isNat#(activate(N)))
          isNatIList#(V) -> c_22(isNatList#(activate(V)))
      - Weak TRS:
          0() -> n__0()
          U11(tt()) -> tt()
          U21(tt()) -> tt()
          U51(tt(),V2) -> U52(isNatList(activate(V2)))
          U52(tt()) -> tt()
          activate(X) -> X
          activate(n__0()) -> 0()
          activate(n__cons(X1,X2)) -> cons(X1,X2)
          activate(n__length(X)) -> length(X)
          activate(n__nil()) -> nil()
          activate(n__s(X)) -> s(X)
          activate(n__zeros()) -> zeros()
          cons(X1,X2) -> n__cons(X1,X2)
          isNat(n__0()) -> tt()
          isNat(n__length(V1)) -> U11(isNatList(activate(V1)))
          isNat(n__s(V1)) -> U21(isNat(activate(V1)))
          isNatList(n__cons(V1,V2)) -> U51(isNat(activate(V1)),activate(V2))
          isNatList(n__nil()) -> tt()
          length(X) -> n__length(X)
          nil() -> n__nil()
          s(X) -> n__s(X)
          zeros() -> cons(0(),n__zeros())
          zeros() -> n__zeros()
      - Signature:
          {0/0,U11/1,U21/1,U31/1,U41/2,U42/1,U51/2,U52/1,U61/3,U62/2,activate/1,cons/2,isNat/1,isNatIList/1
          ,isNatList/1,length/1,nil/0,s/1,zeros/0,0#/0,U11#/1,U21#/1,U31#/1,U41#/2,U42#/1,U51#/2,U52#/1,U61#/3,U62#/2
          ,activate#/1,cons#/2,isNat#/1,isNatIList#/1,isNatList#/1,length#/1,nil#/0,s#/1,zeros#/0} / {n__0/0,n__cons/2
          ,n__length/1,n__nil/0,n__s/1,n__zeros/0,tt/0,c_1/0,c_2/0,c_3/0,c_4/0,c_5/1,c_6/0,c_7/1,c_8/0,c_9/1,c_10/3
          ,c_11/0,c_12/1,c_13/1,c_14/1,c_15/1,c_16/1,c_17/1,c_18/0,c_19/0,c_20/1,c_21/1,c_22/1,c_23/2,c_24/0,c_25/2
          ,c_26/0,c_27/0,c_28/0,c_29/0,c_30/2,c_31/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {0#,U11#,U21#,U31#,U41#,U42#,U51#,U52#,U61#,U62#,activate#
          ,cons#,isNat#,isNatIList#,isNatList#,length#,nil#,s#,zeros#} and constructors {n__0,n__cons,n__length,n__nil
          ,n__s,n__zeros,tt}
  + Applied Processor:
      EmptyProcessor
  + Details:
      The problem is still open.
MAYBE