Termination w.r.t. Q of the following Term Rewriting System could be proven:

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

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

Q is empty.


QTRS
  ↳ DependencyPairsProof

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

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

Q is empty.

Using Dependency Pairs [1,15] we result in the following initial DP problem:
Q DP problem:
The TRS P consists of the following rules:

U111(tt, N, XS) → ACTIVATE(XS)
AFTERNTH(N, XS) → U111(tt, N, XS)
U421(tt, N, XS) → AFTERNTH(activate(N), activate(XS))
U631(tt, N, X, XS) → SPLITAT(activate(N), activate(XS))
TAIL(cons(N, XS)) → U711(tt, activate(XS))
U631(tt, N, X, XS) → ACTIVATE(XS)
ACTIVATE(n__s(X)) → ACTIVATE(X)
U611(tt, N, X, XS) → ACTIVATE(XS)
U611(tt, N, X, XS) → U621(tt, activate(N), activate(X), activate(XS))
U821(tt, N, XS) → ACTIVATE(N)
U211(tt, X) → U221(tt, activate(X))
U821(tt, N, XS) → SPLITAT(activate(N), activate(XS))
U121(tt, N, XS) → ACTIVATE(XS)
U721(tt, XS) → ACTIVATE(XS)
SND(pair(X, Y)) → U511(tt, Y)
U811(tt, N, XS) → ACTIVATE(XS)
ACTIVATE(n__s(X)) → S(activate(X))
U421(tt, N, XS) → ACTIVATE(N)
U621(tt, N, X, XS) → ACTIVATE(XS)
U111(tt, N, XS) → ACTIVATE(N)
U631(tt, N, X, XS) → ACTIVATE(X)
U521(tt, Y) → ACTIVATE(Y)
TAKE(N, XS) → U811(tt, N, XS)
U631(tt, N, X, XS) → U641(splitAt(activate(N), activate(XS)), activate(X))
SEL(N, XS) → U411(tt, N, XS)
U641(pair(YS, ZS), X) → ACTIVATE(X)
FST(pair(X, Y)) → U211(tt, X)
U611(tt, N, X, XS) → ACTIVATE(X)
SPLITAT(s(N), cons(X, XS)) → ACTIVATE(XS)
U511(tt, Y) → ACTIVATE(Y)
HEAD(cons(N, XS)) → U311(tt, N)
U111(tt, N, XS) → U121(tt, activate(N), activate(XS))
U311(tt, N) → ACTIVATE(N)
U811(tt, N, XS) → U821(tt, activate(N), activate(XS))
U621(tt, N, X, XS) → ACTIVATE(N)
U821(tt, N, XS) → FST(splitAt(activate(N), activate(XS)))
U411(tt, N, XS) → ACTIVATE(XS)
U811(tt, N, XS) → ACTIVATE(N)
U121(tt, N, XS) → ACTIVATE(N)
TAIL(cons(N, XS)) → ACTIVATE(XS)
ACTIVATE(n__natsFrom(X)) → NATSFROM(activate(X))
U311(tt, N) → U321(tt, activate(N))
U121(tt, N, XS) → SND(splitAt(activate(N), activate(XS)))
U821(tt, N, XS) → ACTIVATE(XS)
U411(tt, N, XS) → ACTIVATE(N)
U711(tt, XS) → U721(tt, activate(XS))
U221(tt, X) → ACTIVATE(X)
U611(tt, N, X, XS) → ACTIVATE(N)
U511(tt, Y) → U521(tt, activate(Y))
U421(tt, N, XS) → HEAD(afterNth(activate(N), activate(XS)))
U211(tt, X) → ACTIVATE(X)
ACTIVATE(n__natsFrom(X)) → ACTIVATE(X)
U121(tt, N, XS) → SPLITAT(activate(N), activate(XS))
U711(tt, XS) → ACTIVATE(XS)
U321(tt, N) → ACTIVATE(N)
U631(tt, N, X, XS) → ACTIVATE(N)
U621(tt, N, X, XS) → ACTIVATE(X)
U421(tt, N, XS) → ACTIVATE(XS)
SPLITAT(s(N), cons(X, XS)) → U611(tt, N, X, activate(XS))
U411(tt, N, XS) → U421(tt, activate(N), activate(XS))
U621(tt, N, X, XS) → U631(tt, activate(N), activate(X), activate(XS))

The TRS R consists of the following rules:

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

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

↳ QTRS
  ↳ DependencyPairsProof
QDP
      ↳ DependencyGraphProof

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

U111(tt, N, XS) → ACTIVATE(XS)
AFTERNTH(N, XS) → U111(tt, N, XS)
U421(tt, N, XS) → AFTERNTH(activate(N), activate(XS))
U631(tt, N, X, XS) → SPLITAT(activate(N), activate(XS))
TAIL(cons(N, XS)) → U711(tt, activate(XS))
U631(tt, N, X, XS) → ACTIVATE(XS)
ACTIVATE(n__s(X)) → ACTIVATE(X)
U611(tt, N, X, XS) → ACTIVATE(XS)
U611(tt, N, X, XS) → U621(tt, activate(N), activate(X), activate(XS))
U821(tt, N, XS) → ACTIVATE(N)
U211(tt, X) → U221(tt, activate(X))
U821(tt, N, XS) → SPLITAT(activate(N), activate(XS))
U121(tt, N, XS) → ACTIVATE(XS)
U721(tt, XS) → ACTIVATE(XS)
SND(pair(X, Y)) → U511(tt, Y)
U811(tt, N, XS) → ACTIVATE(XS)
ACTIVATE(n__s(X)) → S(activate(X))
U421(tt, N, XS) → ACTIVATE(N)
U621(tt, N, X, XS) → ACTIVATE(XS)
U111(tt, N, XS) → ACTIVATE(N)
U631(tt, N, X, XS) → ACTIVATE(X)
U521(tt, Y) → ACTIVATE(Y)
TAKE(N, XS) → U811(tt, N, XS)
U631(tt, N, X, XS) → U641(splitAt(activate(N), activate(XS)), activate(X))
SEL(N, XS) → U411(tt, N, XS)
U641(pair(YS, ZS), X) → ACTIVATE(X)
FST(pair(X, Y)) → U211(tt, X)
U611(tt, N, X, XS) → ACTIVATE(X)
SPLITAT(s(N), cons(X, XS)) → ACTIVATE(XS)
U511(tt, Y) → ACTIVATE(Y)
HEAD(cons(N, XS)) → U311(tt, N)
U111(tt, N, XS) → U121(tt, activate(N), activate(XS))
U311(tt, N) → ACTIVATE(N)
U811(tt, N, XS) → U821(tt, activate(N), activate(XS))
U621(tt, N, X, XS) → ACTIVATE(N)
U821(tt, N, XS) → FST(splitAt(activate(N), activate(XS)))
U411(tt, N, XS) → ACTIVATE(XS)
U811(tt, N, XS) → ACTIVATE(N)
U121(tt, N, XS) → ACTIVATE(N)
TAIL(cons(N, XS)) → ACTIVATE(XS)
ACTIVATE(n__natsFrom(X)) → NATSFROM(activate(X))
U311(tt, N) → U321(tt, activate(N))
U121(tt, N, XS) → SND(splitAt(activate(N), activate(XS)))
U821(tt, N, XS) → ACTIVATE(XS)
U411(tt, N, XS) → ACTIVATE(N)
U711(tt, XS) → U721(tt, activate(XS))
U221(tt, X) → ACTIVATE(X)
U611(tt, N, X, XS) → ACTIVATE(N)
U511(tt, Y) → U521(tt, activate(Y))
U421(tt, N, XS) → HEAD(afterNth(activate(N), activate(XS)))
U211(tt, X) → ACTIVATE(X)
ACTIVATE(n__natsFrom(X)) → ACTIVATE(X)
U121(tt, N, XS) → SPLITAT(activate(N), activate(XS))
U711(tt, XS) → ACTIVATE(XS)
U321(tt, N) → ACTIVATE(N)
U631(tt, N, X, XS) → ACTIVATE(N)
U621(tt, N, X, XS) → ACTIVATE(X)
U421(tt, N, XS) → ACTIVATE(XS)
SPLITAT(s(N), cons(X, XS)) → U611(tt, N, X, activate(XS))
U411(tt, N, XS) → U421(tt, activate(N), activate(XS))
U621(tt, N, X, XS) → U631(tt, activate(N), activate(X), activate(XS))

The TRS R consists of the following rules:

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 2 SCCs with 55 less nodes.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ AND
QDP
            ↳ UsableRulesProof
          ↳ QDP

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

ACTIVATE(n__natsFrom(X)) → ACTIVATE(X)
ACTIVATE(n__s(X)) → ACTIVATE(X)

The TRS R consists of the following rules:

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We can use the usable rules and reduction pair processor [15] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its argument. Then, we can delete all non-usable rules [17] from R.

↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ AND
          ↳ QDP
            ↳ UsableRulesProof
QDP
                ↳ QDPSizeChangeProof
          ↳ QDP

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

ACTIVATE(n__natsFrom(X)) → ACTIVATE(X)
ACTIVATE(n__s(X)) → ACTIVATE(X)

R is empty.
Q is empty.
We have to consider all minimal (P,Q,R)-chains.
By using the subterm criterion [20] together with the size-change analysis [32] we have proven that there are no infinite chains for this DP problem.

From the DPs we obtained the following set of size-change graphs:



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ AND
          ↳ QDP
QDP
            ↳ QDPOrderProof

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

U631(tt, N, X, XS) → SPLITAT(activate(N), activate(XS))
U611(tt, N, X, XS) → U621(tt, activate(N), activate(X), activate(XS))
SPLITAT(s(N), cons(X, XS)) → U611(tt, N, X, activate(XS))
U621(tt, N, X, XS) → U631(tt, activate(N), activate(X), activate(XS))

The TRS R consists of the following rules:

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
We use the reduction pair processor [15].


The following pairs can be oriented strictly and are deleted.


SPLITAT(s(N), cons(X, XS)) → U611(tt, N, X, activate(XS))
The remaining pairs can at least be oriented weakly.

U631(tt, N, X, XS) → SPLITAT(activate(N), activate(XS))
U611(tt, N, X, XS) → U621(tt, activate(N), activate(X), activate(XS))
U621(tt, N, X, XS) → U631(tt, activate(N), activate(X), activate(XS))
Used ordering: Polynomial interpretation [25]:

POL(SPLITAT(x1, x2)) = x1   
POL(U611(x1, x2, x3, x4)) = x2   
POL(U621(x1, x2, x3, x4)) = x2   
POL(U631(x1, x2, x3, x4)) = x2   
POL(activate(x1)) = x1   
POL(cons(x1, x2)) = 0   
POL(n__natsFrom(x1)) = 0   
POL(n__s(x1)) = 1 + x1   
POL(natsFrom(x1)) = 0   
POL(s(x1)) = 1 + x1   
POL(tt) = 0   

The following usable rules [17] were oriented:

activate(X) → X
activate(n__s(X)) → s(activate(X))
activate(n__natsFrom(X)) → natsFrom(activate(X))
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
s(X) → n__s(X)
natsFrom(X) → n__natsFrom(X)



↳ QTRS
  ↳ DependencyPairsProof
    ↳ QDP
      ↳ DependencyGraphProof
        ↳ AND
          ↳ QDP
          ↳ QDP
            ↳ QDPOrderProof
QDP
                ↳ DependencyGraphProof

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

U631(tt, N, X, XS) → SPLITAT(activate(N), activate(XS))
U621(tt, N, X, XS) → U631(tt, activate(N), activate(X), activate(XS))
U611(tt, N, X, XS) → U621(tt, activate(N), activate(X), activate(XS))

The TRS R consists of the following rules:

U11(tt, N, XS) → U12(tt, activate(N), activate(XS))
U12(tt, N, XS) → snd(splitAt(activate(N), activate(XS)))
U21(tt, X) → U22(tt, activate(X))
U22(tt, X) → activate(X)
U31(tt, N) → U32(tt, activate(N))
U32(tt, N) → activate(N)
U41(tt, N, XS) → U42(tt, activate(N), activate(XS))
U42(tt, N, XS) → head(afterNth(activate(N), activate(XS)))
U51(tt, Y) → U52(tt, activate(Y))
U52(tt, Y) → activate(Y)
U61(tt, N, X, XS) → U62(tt, activate(N), activate(X), activate(XS))
U62(tt, N, X, XS) → U63(tt, activate(N), activate(X), activate(XS))
U63(tt, N, X, XS) → U64(splitAt(activate(N), activate(XS)), activate(X))
U64(pair(YS, ZS), X) → pair(cons(activate(X), YS), ZS)
U71(tt, XS) → U72(tt, activate(XS))
U72(tt, XS) → activate(XS)
U81(tt, N, XS) → U82(tt, activate(N), activate(XS))
U82(tt, N, XS) → fst(splitAt(activate(N), activate(XS)))
afterNth(N, XS) → U11(tt, N, XS)
fst(pair(X, Y)) → U21(tt, X)
head(cons(N, XS)) → U31(tt, N)
natsFrom(N) → cons(N, n__natsFrom(n__s(N)))
sel(N, XS) → U41(tt, N, XS)
snd(pair(X, Y)) → U51(tt, Y)
splitAt(0, XS) → pair(nil, XS)
splitAt(s(N), cons(X, XS)) → U61(tt, N, X, activate(XS))
tail(cons(N, XS)) → U71(tt, activate(XS))
take(N, XS) → U81(tt, N, XS)
natsFrom(X) → n__natsFrom(X)
s(X) → n__s(X)
activate(n__natsFrom(X)) → natsFrom(activate(X))
activate(n__s(X)) → s(activate(X))
activate(X) → X

Q is empty.
We have to consider all minimal (P,Q,R)-chains.
The approximation of the Dependency Graph [15,17,22] contains 0 SCCs with 3 less nodes.