(0) Obligation:

Q restricted rewrite system:
The TRS R consists of the following rules:

a__zeroscons(0, zeros)
a__U11(tt) → tt
a__U21(tt) → tt
a__U31(tt) → tt
a__U41(tt, V2) → a__U42(a__isNatIList(V2))
a__U42(tt) → tt
a__U51(tt, V2) → a__U52(a__isNatList(V2))
a__U52(tt) → tt
a__U61(tt, V2) → a__U62(a__isNatIList(V2))
a__U62(tt) → tt
a__U71(tt, L, N) → a__U72(a__isNat(N), L)
a__U72(tt, L) → s(a__length(mark(L)))
a__U81(tt) → nil
a__U91(tt, IL, M, N) → a__U92(a__isNat(M), IL, M, N)
a__U92(tt, IL, M, N) → a__U93(a__isNat(N), IL, M, N)
a__U93(tt, IL, M, N) → cons(mark(N), take(M, IL))
a__isNat(0) → tt
a__isNat(length(V1)) → a__U11(a__isNatList(V1))
a__isNat(s(V1)) → a__U21(a__isNat(V1))
a__isNatIList(V) → a__U31(a__isNatList(V))
a__isNatIList(zeros) → tt
a__isNatIList(cons(V1, V2)) → a__U41(a__isNat(V1), V2)
a__isNatList(nil) → tt
a__isNatList(cons(V1, V2)) → a__U51(a__isNat(V1), V2)
a__isNatList(take(V1, V2)) → a__U61(a__isNat(V1), V2)
a__length(nil) → 0
a__length(cons(N, L)) → a__U71(a__isNatList(L), L, N)
a__take(0, IL) → a__U81(a__isNatIList(IL))
a__take(s(M), cons(N, IL)) → a__U91(a__isNatIList(IL), IL, M, N)
mark(zeros) → a__zeros
mark(U11(X)) → a__U11(mark(X))
mark(U21(X)) → a__U21(mark(X))
mark(U31(X)) → a__U31(mark(X))
mark(U41(X1, X2)) → a__U41(mark(X1), X2)
mark(U42(X)) → a__U42(mark(X))
mark(isNatIList(X)) → a__isNatIList(X)
mark(U51(X1, X2)) → a__U51(mark(X1), X2)
mark(U52(X)) → a__U52(mark(X))
mark(isNatList(X)) → a__isNatList(X)
mark(U61(X1, X2)) → a__U61(mark(X1), X2)
mark(U62(X)) → a__U62(mark(X))
mark(U71(X1, X2, X3)) → a__U71(mark(X1), X2, X3)
mark(U72(X1, X2)) → a__U72(mark(X1), X2)
mark(isNat(X)) → a__isNat(X)
mark(length(X)) → a__length(mark(X))
mark(U81(X)) → a__U81(mark(X))
mark(U91(X1, X2, X3, X4)) → a__U91(mark(X1), X2, X3, X4)
mark(U92(X1, X2, X3, X4)) → a__U92(mark(X1), X2, X3, X4)
mark(U93(X1, X2, X3, X4)) → a__U93(mark(X1), X2, X3, X4)
mark(take(X1, X2)) → a__take(mark(X1), mark(X2))
mark(cons(X1, X2)) → cons(mark(X1), X2)
mark(0) → 0
mark(tt) → tt
mark(s(X)) → s(mark(X))
mark(nil) → nil
a__zeroszeros
a__U11(X) → U11(X)
a__U21(X) → U21(X)
a__U31(X) → U31(X)
a__U41(X1, X2) → U41(X1, X2)
a__U42(X) → U42(X)
a__isNatIList(X) → isNatIList(X)
a__U51(X1, X2) → U51(X1, X2)
a__U52(X) → U52(X)
a__isNatList(X) → isNatList(X)
a__U61(X1, X2) → U61(X1, X2)
a__U62(X) → U62(X)
a__U71(X1, X2, X3) → U71(X1, X2, X3)
a__U72(X1, X2) → U72(X1, X2)
a__isNat(X) → isNat(X)
a__length(X) → length(X)
a__U81(X) → U81(X)
a__U91(X1, X2, X3, X4) → U91(X1, X2, X3, X4)
a__U92(X1, X2, X3, X4) → U92(X1, X2, X3, X4)
a__U93(X1, X2, X3, X4) → U93(X1, X2, X3, X4)
a__take(X1, X2) → take(X1, X2)

Q is empty.

(1) DependencyPairsProof (EQUIVALENT transformation)

Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem.

(2) Obligation:

Q DP problem:
The TRS P consists of the following rules:

A__U41(tt, V2) → A__U42(a__isNatIList(V2))
A__U41(tt, V2) → A__ISNATILIST(V2)
A__U51(tt, V2) → A__U52(a__isNatList(V2))
A__U51(tt, V2) → A__ISNATLIST(V2)
A__U61(tt, V2) → A__U62(a__isNatIList(V2))
A__U61(tt, V2) → A__ISNATILIST(V2)
A__U71(tt, L, N) → A__U72(a__isNat(N), L)
A__U71(tt, L, N) → A__ISNAT(N)
A__U72(tt, L) → A__LENGTH(mark(L))
A__U72(tt, L) → MARK(L)
A__U91(tt, IL, M, N) → A__U92(a__isNat(M), IL, M, N)
A__U91(tt, IL, M, N) → A__ISNAT(M)
A__U92(tt, IL, M, N) → A__U93(a__isNat(N), IL, M, N)
A__U92(tt, IL, M, N) → A__ISNAT(N)
A__U93(tt, IL, M, N) → MARK(N)
A__ISNAT(length(V1)) → A__U11(a__isNatList(V1))
A__ISNAT(length(V1)) → A__ISNATLIST(V1)
A__ISNAT(s(V1)) → A__U21(a__isNat(V1))
A__ISNAT(s(V1)) → A__ISNAT(V1)
A__ISNATILIST(V) → A__U31(a__isNatList(V))
A__ISNATILIST(V) → A__ISNATLIST(V)
A__ISNATILIST(cons(V1, V2)) → A__U41(a__isNat(V1), V2)
A__ISNATILIST(cons(V1, V2)) → A__ISNAT(V1)
A__ISNATLIST(cons(V1, V2)) → A__U51(a__isNat(V1), V2)
A__ISNATLIST(cons(V1, V2)) → A__ISNAT(V1)
A__ISNATLIST(take(V1, V2)) → A__U61(a__isNat(V1), V2)
A__ISNATLIST(take(V1, V2)) → A__ISNAT(V1)
A__LENGTH(cons(N, L)) → A__U71(a__isNatList(L), L, N)
A__LENGTH(cons(N, L)) → A__ISNATLIST(L)
A__TAKE(0, IL) → A__U81(a__isNatIList(IL))
A__TAKE(0, IL) → A__ISNATILIST(IL)
A__TAKE(s(M), cons(N, IL)) → A__U91(a__isNatIList(IL), IL, M, N)
A__TAKE(s(M), cons(N, IL)) → A__ISNATILIST(IL)
MARK(zeros) → A__ZEROS
MARK(U11(X)) → A__U11(mark(X))
MARK(U11(X)) → MARK(X)
MARK(U21(X)) → A__U21(mark(X))
MARK(U21(X)) → MARK(X)
MARK(U31(X)) → A__U31(mark(X))
MARK(U31(X)) → MARK(X)
MARK(U41(X1, X2)) → A__U41(mark(X1), X2)
MARK(U41(X1, X2)) → MARK(X1)
MARK(U42(X)) → A__U42(mark(X))
MARK(U42(X)) → MARK(X)
MARK(isNatIList(X)) → A__ISNATILIST(X)
MARK(U51(X1, X2)) → A__U51(mark(X1), X2)
MARK(U51(X1, X2)) → MARK(X1)
MARK(U52(X)) → A__U52(mark(X))
MARK(U52(X)) → MARK(X)
MARK(isNatList(X)) → A__ISNATLIST(X)
MARK(U61(X1, X2)) → A__U61(mark(X1), X2)
MARK(U61(X1, X2)) → MARK(X1)
MARK(U62(X)) → A__U62(mark(X))
MARK(U62(X)) → MARK(X)
MARK(U71(X1, X2, X3)) → A__U71(mark(X1), X2, X3)
MARK(U71(X1, X2, X3)) → MARK(X1)
MARK(U72(X1, X2)) → A__U72(mark(X1), X2)
MARK(U72(X1, X2)) → MARK(X1)
MARK(isNat(X)) → A__ISNAT(X)
MARK(length(X)) → A__LENGTH(mark(X))
MARK(length(X)) → MARK(X)
MARK(U81(X)) → A__U81(mark(X))
MARK(U81(X)) → MARK(X)
MARK(U91(X1, X2, X3, X4)) → A__U91(mark(X1), X2, X3, X4)
MARK(U91(X1, X2, X3, X4)) → MARK(X1)
MARK(U92(X1, X2, X3, X4)) → A__U92(mark(X1), X2, X3, X4)
MARK(U92(X1, X2, X3, X4)) → MARK(X1)
MARK(U93(X1, X2, X3, X4)) → A__U93(mark(X1), X2, X3, X4)
MARK(U93(X1, X2, X3, X4)) → MARK(X1)
MARK(take(X1, X2)) → A__TAKE(mark(X1), mark(X2))
MARK(take(X1, X2)) → MARK(X1)
MARK(take(X1, X2)) → MARK(X2)
MARK(cons(X1, X2)) → MARK(X1)
MARK(s(X)) → MARK(X)

The TRS R consists of the following rules:

a__zeroscons(0, zeros)
a__U11(tt) → tt
a__U21(tt) → tt
a__U31(tt) → tt
a__U41(tt, V2) → a__U42(a__isNatIList(V2))
a__U42(tt) → tt
a__U51(tt, V2) → a__U52(a__isNatList(V2))
a__U52(tt) → tt
a__U61(tt, V2) → a__U62(a__isNatIList(V2))
a__U62(tt) → tt
a__U71(tt, L, N) → a__U72(a__isNat(N), L)
a__U72(tt, L) → s(a__length(mark(L)))
a__U81(tt) → nil
a__U91(tt, IL, M, N) → a__U92(a__isNat(M), IL, M, N)
a__U92(tt, IL, M, N) → a__U93(a__isNat(N), IL, M, N)
a__U93(tt, IL, M, N) → cons(mark(N), take(M, IL))
a__isNat(0) → tt
a__isNat(length(V1)) → a__U11(a__isNatList(V1))
a__isNat(s(V1)) → a__U21(a__isNat(V1))
a__isNatIList(V) → a__U31(a__isNatList(V))
a__isNatIList(zeros) → tt
a__isNatIList(cons(V1, V2)) → a__U41(a__isNat(V1), V2)
a__isNatList(nil) → tt
a__isNatList(cons(V1, V2)) → a__U51(a__isNat(V1), V2)
a__isNatList(take(V1, V2)) → a__U61(a__isNat(V1), V2)
a__length(nil) → 0
a__length(cons(N, L)) → a__U71(a__isNatList(L), L, N)
a__take(0, IL) → a__U81(a__isNatIList(IL))
a__take(s(M), cons(N, IL)) → a__U91(a__isNatIList(IL), IL, M, N)
mark(zeros) → a__zeros
mark(U11(X)) → a__U11(mark(X))
mark(U21(X)) → a__U21(mark(X))
mark(U31(X)) → a__U31(mark(X))
mark(U41(X1, X2)) → a__U41(mark(X1), X2)
mark(U42(X)) → a__U42(mark(X))
mark(isNatIList(X)) → a__isNatIList(X)
mark(U51(X1, X2)) → a__U51(mark(X1), X2)
mark(U52(X)) → a__U52(mark(X))
mark(isNatList(X)) → a__isNatList(X)
mark(U61(X1, X2)) → a__U61(mark(X1), X2)
mark(U62(X)) → a__U62(mark(X))
mark(U71(X1, X2, X3)) → a__U71(mark(X1), X2, X3)
mark(U72(X1, X2)) → a__U72(mark(X1), X2)
mark(isNat(X)) → a__isNat(X)
mark(length(X)) → a__length(mark(X))
mark(U81(X)) → a__U81(mark(X))
mark(U91(X1, X2, X3, X4)) → a__U91(mark(X1), X2, X3, X4)
mark(U92(X1, X2, X3, X4)) → a__U92(mark(X1), X2, X3, X4)
mark(U93(X1, X2, X3, X4)) → a__U93(mark(X1), X2, X3, X4)
mark(take(X1, X2)) → a__take(mark(X1), mark(X2))
mark(cons(X1, X2)) → cons(mark(X1), X2)
mark(0) → 0
mark(tt) → tt
mark(s(X)) → s(mark(X))
mark(nil) → nil
a__zeroszeros
a__U11(X) → U11(X)
a__U21(X) → U21(X)
a__U31(X) → U31(X)
a__U41(X1, X2) → U41(X1, X2)
a__U42(X) → U42(X)
a__isNatIList(X) → isNatIList(X)
a__U51(X1, X2) → U51(X1, X2)
a__U52(X) → U52(X)
a__isNatList(X) → isNatList(X)
a__U61(X1, X2) → U61(X1, X2)
a__U62(X) → U62(X)
a__U71(X1, X2, X3) → U71(X1, X2, X3)
a__U72(X1, X2) → U72(X1, X2)
a__isNat(X) → isNat(X)
a__length(X) → length(X)
a__U81(X) → U81(X)
a__U91(X1, X2, X3, X4) → U91(X1, X2, X3, X4)
a__U92(X1, X2, X3, X4) → U92(X1, X2, X3, X4)
a__U93(X1, X2, X3, X4) → U93(X1, X2, X3, X4)
a__take(X1, X2) → take(X1, X2)

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

(3) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 2 SCCs with 27 less nodes.

(4) Complex Obligation (AND)

(5) Obligation:

Q DP problem:
The TRS P consists of the following rules:

A__U41(tt, V2) → A__ISNATILIST(V2)
A__ISNATILIST(V) → A__ISNATLIST(V)
A__ISNATLIST(cons(V1, V2)) → A__U51(a__isNat(V1), V2)
A__U51(tt, V2) → A__ISNATLIST(V2)
A__ISNATLIST(cons(V1, V2)) → A__ISNAT(V1)
A__ISNAT(length(V1)) → A__ISNATLIST(V1)
A__ISNATLIST(take(V1, V2)) → A__U61(a__isNat(V1), V2)
A__U61(tt, V2) → A__ISNATILIST(V2)
A__ISNATILIST(cons(V1, V2)) → A__U41(a__isNat(V1), V2)
A__ISNATILIST(cons(V1, V2)) → A__ISNAT(V1)
A__ISNAT(s(V1)) → A__ISNAT(V1)
A__ISNATLIST(take(V1, V2)) → A__ISNAT(V1)

The TRS R consists of the following rules:

a__zeroscons(0, zeros)
a__U11(tt) → tt
a__U21(tt) → tt
a__U31(tt) → tt
a__U41(tt, V2) → a__U42(a__isNatIList(V2))
a__U42(tt) → tt
a__U51(tt, V2) → a__U52(a__isNatList(V2))
a__U52(tt) → tt
a__U61(tt, V2) → a__U62(a__isNatIList(V2))
a__U62(tt) → tt
a__U71(tt, L, N) → a__U72(a__isNat(N), L)
a__U72(tt, L) → s(a__length(mark(L)))
a__U81(tt) → nil
a__U91(tt, IL, M, N) → a__U92(a__isNat(M), IL, M, N)
a__U92(tt, IL, M, N) → a__U93(a__isNat(N), IL, M, N)
a__U93(tt, IL, M, N) → cons(mark(N), take(M, IL))
a__isNat(0) → tt
a__isNat(length(V1)) → a__U11(a__isNatList(V1))
a__isNat(s(V1)) → a__U21(a__isNat(V1))
a__isNatIList(V) → a__U31(a__isNatList(V))
a__isNatIList(zeros) → tt
a__isNatIList(cons(V1, V2)) → a__U41(a__isNat(V1), V2)
a__isNatList(nil) → tt
a__isNatList(cons(V1, V2)) → a__U51(a__isNat(V1), V2)
a__isNatList(take(V1, V2)) → a__U61(a__isNat(V1), V2)
a__length(nil) → 0
a__length(cons(N, L)) → a__U71(a__isNatList(L), L, N)
a__take(0, IL) → a__U81(a__isNatIList(IL))
a__take(s(M), cons(N, IL)) → a__U91(a__isNatIList(IL), IL, M, N)
mark(zeros) → a__zeros
mark(U11(X)) → a__U11(mark(X))
mark(U21(X)) → a__U21(mark(X))
mark(U31(X)) → a__U31(mark(X))
mark(U41(X1, X2)) → a__U41(mark(X1), X2)
mark(U42(X)) → a__U42(mark(X))
mark(isNatIList(X)) → a__isNatIList(X)
mark(U51(X1, X2)) → a__U51(mark(X1), X2)
mark(U52(X)) → a__U52(mark(X))
mark(isNatList(X)) → a__isNatList(X)
mark(U61(X1, X2)) → a__U61(mark(X1), X2)
mark(U62(X)) → a__U62(mark(X))
mark(U71(X1, X2, X3)) → a__U71(mark(X1), X2, X3)
mark(U72(X1, X2)) → a__U72(mark(X1), X2)
mark(isNat(X)) → a__isNat(X)
mark(length(X)) → a__length(mark(X))
mark(U81(X)) → a__U81(mark(X))
mark(U91(X1, X2, X3, X4)) → a__U91(mark(X1), X2, X3, X4)
mark(U92(X1, X2, X3, X4)) → a__U92(mark(X1), X2, X3, X4)
mark(U93(X1, X2, X3, X4)) → a__U93(mark(X1), X2, X3, X4)
mark(take(X1, X2)) → a__take(mark(X1), mark(X2))
mark(cons(X1, X2)) → cons(mark(X1), X2)
mark(0) → 0
mark(tt) → tt
mark(s(X)) → s(mark(X))
mark(nil) → nil
a__zeroszeros
a__U11(X) → U11(X)
a__U21(X) → U21(X)
a__U31(X) → U31(X)
a__U41(X1, X2) → U41(X1, X2)
a__U42(X) → U42(X)
a__isNatIList(X) → isNatIList(X)
a__U51(X1, X2) → U51(X1, X2)
a__U52(X) → U52(X)
a__isNatList(X) → isNatList(X)
a__U61(X1, X2) → U61(X1, X2)
a__U62(X) → U62(X)
a__U71(X1, X2, X3) → U71(X1, X2, X3)
a__U72(X1, X2) → U72(X1, X2)
a__isNat(X) → isNat(X)
a__length(X) → length(X)
a__U81(X) → U81(X)
a__U91(X1, X2, X3, X4) → U91(X1, X2, X3, X4)
a__U92(X1, X2, X3, X4) → U92(X1, X2, X3, X4)
a__U93(X1, X2, X3, X4) → U93(X1, X2, X3, X4)
a__take(X1, X2) → take(X1, X2)

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

(6) QDPOrderProof (EQUIVALENT transformation)

We use the reduction pair processor [LPAR04].


The following pairs can be oriented strictly and are deleted.


A__U41(tt, V2) → A__ISNATILIST(V2)
A__ISNATLIST(cons(V1, V2)) → A__U51(a__isNat(V1), V2)
A__ISNATLIST(cons(V1, V2)) → A__ISNAT(V1)
A__ISNATLIST(take(V1, V2)) → A__U61(a__isNat(V1), V2)
A__U61(tt, V2) → A__ISNATILIST(V2)
A__ISNATILIST(cons(V1, V2)) → A__U41(a__isNat(V1), V2)
A__ISNATILIST(cons(V1, V2)) → A__ISNAT(V1)
A__ISNAT(s(V1)) → A__ISNAT(V1)
A__ISNATLIST(take(V1, V2)) → A__ISNAT(V1)
The remaining pairs can at least be oriented weakly.
Used ordering: Combined order from the following AFS and order.
A__U41(x1, x2)  =  A__U41(x2)
tt  =  tt
A__ISNATILIST(x1)  =  x1
A__ISNATLIST(x1)  =  x1
cons(x1, x2)  =  cons(x1, x2)
A__U51(x1, x2)  =  x2
a__isNat(x1)  =  x1
A__ISNAT(x1)  =  x1
length(x1)  =  x1
take(x1, x2)  =  take(x1, x2)
A__U61(x1, x2)  =  A__U61(x2)
s(x1)  =  s(x1)
a__U42(x1)  =  a__U42(x1)
U42(x1)  =  U42(x1)
a__U41(x1, x2)  =  a__U41
U41(x1, x2)  =  U41(x1)
a__U51(x1, x2)  =  a__U51(x1)
U51(x1, x2)  =  U51(x1, x2)
a__isNatIList(x1)  =  x1
isNatIList(x1)  =  isNatIList(x1)
a__U11(x1)  =  a__U11
U11(x1)  =  U11
a__U31(x1)  =  x1
U31(x1)  =  U31
a__U21(x1)  =  a__U21
U21(x1)  =  U21
a__U52(x1)  =  a__U52(x1)
a__isNatList(x1)  =  a__isNatList(x1)
a__U61(x1, x2)  =  a__U61(x1, x2)
a__U62(x1)  =  a__U62(x1)
0  =  0
zeros  =  zeros
nil  =  nil
isNat(x1)  =  x1
U61(x1, x2)  =  U61(x1)
U62(x1)  =  U62
U52(x1)  =  U52
isNatList(x1)  =  isNatList

Recursive path order with status [RPO].
Quasi-Precedence:
[tt, zeros] > aU421 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
[tt, zeros] > aU521 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
[tt, zeros] > aU621 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
take2 > AU611 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
take2 > aU612 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
s1 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U421 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
[aU41, U411] > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
aU511 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
isNatIList1 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U11 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U31 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U21 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
0 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
nil > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U611 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U62 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]
U52 > [AU411, cons2, U512, aU11, aU21, aisNatList1, isNatList]

Status:
aU521: [1]
U411: multiset
U31: multiset
aU511: multiset
U11: multiset
take2: multiset
aU41: []
U512: multiset
tt: multiset
aU421: multiset
zeros: multiset
isNatIList1: multiset
AU411: multiset
s1: [1]
aisNatList1: multiset
nil: multiset
aU621: [1]
U21: []
aU612: multiset
U611: multiset
U62: multiset
isNatList: multiset
aU11: multiset
U52: multiset
0: multiset
cons2: multiset
U421: multiset
aU21: multiset
AU611: multiset


The following usable rules [FROCOS05] were oriented: none

(7) Obligation:

Q DP problem:
The TRS P consists of the following rules:

A__ISNATILIST(V) → A__ISNATLIST(V)
A__U51(tt, V2) → A__ISNATLIST(V2)
A__ISNAT(length(V1)) → A__ISNATLIST(V1)

The TRS R consists of the following rules:

a__zeroscons(0, zeros)
a__U11(tt) → tt
a__U21(tt) → tt
a__U31(tt) → tt
a__U41(tt, V2) → a__U42(a__isNatIList(V2))
a__U42(tt) → tt
a__U51(tt, V2) → a__U52(a__isNatList(V2))
a__U52(tt) → tt
a__U61(tt, V2) → a__U62(a__isNatIList(V2))
a__U62(tt) → tt
a__U71(tt, L, N) → a__U72(a__isNat(N), L)
a__U72(tt, L) → s(a__length(mark(L)))
a__U81(tt) → nil
a__U91(tt, IL, M, N) → a__U92(a__isNat(M), IL, M, N)
a__U92(tt, IL, M, N) → a__U93(a__isNat(N), IL, M, N)
a__U93(tt, IL, M, N) → cons(mark(N), take(M, IL))
a__isNat(0) → tt
a__isNat(length(V1)) → a__U11(a__isNatList(V1))
a__isNat(s(V1)) → a__U21(a__isNat(V1))
a__isNatIList(V) → a__U31(a__isNatList(V))
a__isNatIList(zeros) → tt
a__isNatIList(cons(V1, V2)) → a__U41(a__isNat(V1), V2)
a__isNatList(nil) → tt
a__isNatList(cons(V1, V2)) → a__U51(a__isNat(V1), V2)
a__isNatList(take(V1, V2)) → a__U61(a__isNat(V1), V2)
a__length(nil) → 0
a__length(cons(N, L)) → a__U71(a__isNatList(L), L, N)
a__take(0, IL) → a__U81(a__isNatIList(IL))
a__take(s(M), cons(N, IL)) → a__U91(a__isNatIList(IL), IL, M, N)
mark(zeros) → a__zeros
mark(U11(X)) → a__U11(mark(X))
mark(U21(X)) → a__U21(mark(X))
mark(U31(X)) → a__U31(mark(X))
mark(U41(X1, X2)) → a__U41(mark(X1), X2)
mark(U42(X)) → a__U42(mark(X))
mark(isNatIList(X)) → a__isNatIList(X)
mark(U51(X1, X2)) → a__U51(mark(X1), X2)
mark(U52(X)) → a__U52(mark(X))
mark(isNatList(X)) → a__isNatList(X)
mark(U61(X1, X2)) → a__U61(mark(X1), X2)
mark(U62(X)) → a__U62(mark(X))
mark(U71(X1, X2, X3)) → a__U71(mark(X1), X2, X3)
mark(U72(X1, X2)) → a__U72(mark(X1), X2)
mark(isNat(X)) → a__isNat(X)
mark(length(X)) → a__length(mark(X))
mark(U81(X)) → a__U81(mark(X))
mark(U91(X1, X2, X3, X4)) → a__U91(mark(X1), X2, X3, X4)
mark(U92(X1, X2, X3, X4)) → a__U92(mark(X1), X2, X3, X4)
mark(U93(X1, X2, X3, X4)) → a__U93(mark(X1), X2, X3, X4)
mark(take(X1, X2)) → a__take(mark(X1), mark(X2))
mark(cons(X1, X2)) → cons(mark(X1), X2)
mark(0) → 0
mark(tt) → tt
mark(s(X)) → s(mark(X))
mark(nil) → nil
a__zeroszeros
a__U11(X) → U11(X)
a__U21(X) → U21(X)
a__U31(X) → U31(X)
a__U41(X1, X2) → U41(X1, X2)
a__U42(X) → U42(X)
a__isNatIList(X) → isNatIList(X)
a__U51(X1, X2) → U51(X1, X2)
a__U52(X) → U52(X)
a__isNatList(X) → isNatList(X)
a__U61(X1, X2) → U61(X1, X2)
a__U62(X) → U62(X)
a__U71(X1, X2, X3) → U71(X1, X2, X3)
a__U72(X1, X2) → U72(X1, X2)
a__isNat(X) → isNat(X)
a__length(X) → length(X)
a__U81(X) → U81(X)
a__U91(X1, X2, X3, X4) → U91(X1, X2, X3, X4)
a__U92(X1, X2, X3, X4) → U92(X1, X2, X3, X4)
a__U93(X1, X2, X3, X4) → U93(X1, X2, X3, X4)
a__take(X1, X2) → take(X1, X2)

Q is empty.
We have to consider all minimal (P,Q,R)-chains.

(8) DependencyGraphProof (EQUIVALENT transformation)

The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 3 less nodes.

(9) TRUE

(10) Obligation:

Q DP problem:
The TRS P consists of the following rules:

MARK(U11(X)) → MARK(X)
MARK(U21(X)) → MARK(X)
MARK(U31(X)) → MARK(X)
MARK(U41(X1, X2)) → MARK(X1)
MARK(U42(X)) → MARK(X)
MARK(U51(X1, X2)) → MARK(X1)
MARK(U52(X)) → MARK(X)
MARK(U61(X1, X2)) → MARK(X1)
MARK(U62(X)) → MARK(X)
MARK(U71(X1, X2, X3)) → A__U71(mark(X1), X2, X3)
A__U71(tt, L, N) → A__U72(a__isNat(N), L)
A__U72(tt, L) → A__LENGTH(mark(L))
A__LENGTH(cons(N, L)) → A__U71(a__isNatList(L), L, N)
A__U72(tt, L) → MARK(L)
MARK(U71(X1, X2, X3)) → MARK(X1)
MARK(U72(X1, X2)) → A__U72(mark(X1), X2)
MARK(U72(X1, X2)) → MARK(X1)
MARK(length(X)) → A__LENGTH(mark(X))
MARK(length(X)) → MARK(X)
MARK(U81(X)) → MARK(X)
MARK(U91(X1, X2, X3, X4)) → A__U91(mark(X1), X2, X3, X4)
A__U91(tt, IL, M, N) → A__U92(a__isNat(M), IL, M, N)
A__U92(tt, IL, M, N) → A__U93(a__isNat(N), IL, M, N)
A__U93(tt, IL, M, N) → MARK(N)
MARK(U91(X1, X2, X3, X4)) → MARK(X1)
MARK(U92(X1, X2, X3, X4)) → A__U92(mark(X1), X2, X3, X4)
MARK(U92(X1, X2, X3, X4)) → MARK(X1)
MARK(U93(X1, X2, X3, X4)) → A__U93(mark(X1), X2, X3, X4)
MARK(U93(X1, X2, X3, X4)) → MARK(X1)
MARK(take(X1, X2)) → A__TAKE(mark(X1), mark(X2))
A__TAKE(s(M), cons(N, IL)) → A__U91(a__isNatIList(IL), IL, M, N)
MARK(take(X1, X2)) → MARK(X1)
MARK(take(X1, X2)) → MARK(X2)
MARK(cons(X1, X2)) → MARK(X1)
MARK(s(X)) → MARK(X)

The TRS R consists of the following rules:

a__zeroscons(0, zeros)
a__U11(tt) → tt
a__U21(tt) → tt
a__U31(tt) → tt
a__U41(tt, V2) → a__U42(a__isNatIList(V2))
a__U42(tt) → tt
a__U51(tt, V2) → a__U52(a__isNatList(V2))
a__U52(tt) → tt
a__U61(tt, V2) → a__U62(a__isNatIList(V2))
a__U62(tt) → tt
a__U71(tt, L, N) → a__U72(a__isNat(N), L)
a__U72(tt, L) → s(a__length(mark(L)))
a__U81(tt) → nil
a__U91(tt, IL, M, N) → a__U92(a__isNat(M), IL, M, N)
a__U92(tt, IL, M, N) → a__U93(a__isNat(N), IL, M, N)
a__U93(tt, IL, M, N) → cons(mark(N), take(M, IL))
a__isNat(0) → tt
a__isNat(length(V1)) → a__U11(a__isNatList(V1))
a__isNat(s(V1)) → a__U21(a__isNat(V1))
a__isNatIList(V) → a__U31(a__isNatList(V))
a__isNatIList(zeros) → tt
a__isNatIList(cons(V1, V2)) → a__U41(a__isNat(V1), V2)
a__isNatList(nil) → tt
a__isNatList(cons(V1, V2)) → a__U51(a__isNat(V1), V2)
a__isNatList(take(V1, V2)) → a__U61(a__isNat(V1), V2)
a__length(nil) → 0
a__length(cons(N, L)) → a__U71(a__isNatList(L), L, N)
a__take(0, IL) → a__U81(a__isNatIList(IL))
a__take(s(M), cons(N, IL)) → a__U91(a__isNatIList(IL), IL, M, N)
mark(zeros) → a__zeros
mark(U11(X)) → a__U11(mark(X))
mark(U21(X)) → a__U21(mark(X))
mark(U31(X)) → a__U31(mark(X))
mark(U41(X1, X2)) → a__U41(mark(X1), X2)
mark(U42(X)) → a__U42(mark(X))
mark(isNatIList(X)) → a__isNatIList(X)
mark(U51(X1, X2)) → a__U51(mark(X1), X2)
mark(U52(X)) → a__U52(mark(X))
mark(isNatList(X)) → a__isNatList(X)
mark(U61(X1, X2)) → a__U61(mark(X1), X2)
mark(U62(X)) → a__U62(mark(X))
mark(U71(X1, X2, X3)) → a__U71(mark(X1), X2, X3)
mark(U72(X1, X2)) → a__U72(mark(X1), X2)
mark(isNat(X)) → a__isNat(X)
mark(length(X)) → a__length(mark(X))
mark(U81(X)) → a__U81(mark(X))
mark(U91(X1, X2, X3, X4)) → a__U91(mark(X1), X2, X3, X4)
mark(U92(X1, X2, X3, X4)) → a__U92(mark(X1), X2, X3, X4)
mark(U93(X1, X2, X3, X4)) → a__U93(mark(X1), X2, X3, X4)
mark(take(X1, X2)) → a__take(mark(X1), mark(X2))
mark(cons(X1, X2)) → cons(mark(X1), X2)
mark(0) → 0
mark(tt) → tt
mark(s(X)) → s(mark(X))
mark(nil) → nil
a__zeroszeros
a__U11(X) → U11(X)
a__U21(X) → U21(X)
a__U31(X) → U31(X)
a__U41(X1, X2) → U41(X1, X2)
a__U42(X) → U42(X)
a__isNatIList(X) → isNatIList(X)
a__U51(X1, X2) → U51(X1, X2)
a__U52(X) → U52(X)
a__isNatList(X) → isNatList(X)
a__U61(X1, X2) → U61(X1, X2)
a__U62(X) → U62(X)
a__U71(X1, X2, X3) → U71(X1, X2, X3)
a__U72(X1, X2) → U72(X1, X2)
a__isNat(X) → isNat(X)
a__length(X) → length(X)
a__U81(X) → U81(X)
a__U91(X1, X2, X3, X4) → U91(X1, X2, X3, X4)
a__U92(X1, X2, X3, X4) → U92(X1, X2, X3, X4)
a__U93(X1, X2, X3, X4) → U93(X1, X2, X3, X4)
a__take(X1, X2) → take(X1, X2)

Q is empty.
We have to consider all minimal (P,Q,R)-chains.