MAYBE MAYBE TRS: { fst(pair(X, Y)) -> U21(and(isLNat())), splitAt(0(), XS) -> U71(isLNat()), splitAt(s(N), cons(X)) -> U81(and(isNatural())), U101(tt()) -> fst(splitAt(N, XS)), snd(pair(X, Y)) -> U61(and(isLNat())), U11(tt()) -> snd(splitAt(N, XS)), U21(tt()) -> X, U31(tt()) -> N, U41(tt()) -> cons(N), head(cons(N)) -> U31(and(isNatural())), afterNth(N, XS) -> U11(and(isNatural())), U51(tt()) -> head(afterNth(N, XS)), U61(tt()) -> Y, U71(tt()) -> pair(nil(), XS), U82(pair(YS, ZS)) -> pair(cons(X), ZS), U81(tt()) -> U82(splitAt(N, XS)), U91(tt()) -> XS, and(tt()) -> X, isNatural() -> tt(), isNatural() -> and(isNatural()), isNatural() -> isNatural(), isNatural() -> isLNat(), isLNat() -> tt(), isLNat() -> and(isNatural()), isLNat() -> isNatural(), isLNat() -> isLNat(), isLNat() -> isPLNat(), isPLNat() -> and(isNatural()), isPLNat() -> and(isLNat()), natsFrom(N) -> U41(isNatural()), sel(N, XS) -> U51(and(isNatural())), tail(cons(N)) -> U91(and(isNatural())), take(N, XS) -> U101(and(isNatural())) } DUP: We consider a duplicating system. Trs: { fst(pair(X, Y)) -> U21(and(isLNat())), splitAt(0(), XS) -> U71(isLNat()), splitAt(s(N), cons(X)) -> U81(and(isNatural())), U101(tt()) -> fst(splitAt(N, XS)), snd(pair(X, Y)) -> U61(and(isLNat())), U11(tt()) -> snd(splitAt(N, XS)), U21(tt()) -> X, U31(tt()) -> N, U41(tt()) -> cons(N), head(cons(N)) -> U31(and(isNatural())), afterNth(N, XS) -> U11(and(isNatural())), U51(tt()) -> head(afterNth(N, XS)), U61(tt()) -> Y, U71(tt()) -> pair(nil(), XS), U82(pair(YS, ZS)) -> pair(cons(X), ZS), U81(tt()) -> U82(splitAt(N, XS)), U91(tt()) -> XS, and(tt()) -> X, isNatural() -> tt(), isNatural() -> and(isNatural()), isNatural() -> isNatural(), isNatural() -> isLNat(), isLNat() -> tt(), isLNat() -> and(isNatural()), isLNat() -> isNatural(), isLNat() -> isLNat(), isLNat() -> isPLNat(), isPLNat() -> and(isNatural()), isPLNat() -> and(isLNat()), natsFrom(N) -> U41(isNatural()), sel(N, XS) -> U51(and(isNatural())), tail(cons(N)) -> U91(and(isNatural())), take(N, XS) -> U101(and(isNatural())) } Fail