TRS:
 {                a__zeros() -> cons(0(), zeros()),
             a__U11(tt(), L) -> a__U12(tt(), L),
             a__U12(tt(), L) -> s(a__length(mark(L))),
      a__U21(tt(), IL, M, N) -> a__U22(tt(), IL, M, N),
      a__U22(tt(), IL, M, N) -> a__U23(tt(), IL, M, N),
      a__U23(tt(), IL, M, N) -> cons(mark(N), take(M, IL)),
            a__length(nil()) -> 0(),
       a__length(cons(N, L)) -> a__U11(tt(), L),
            a__take(0(), IL) -> nil(),
  a__take(s(M), cons(N, IL)) -> a__U21(tt(), IL, M, N),
               mark(zeros()) -> a__zeros(),
           mark(U11(X1, X2)) -> a__U11(mark(X1), X2),
           mark(U12(X1, X2)) -> a__U12(mark(X1), X2),
             mark(length(X)) -> a__length(mark(X)),
   mark(U21(X1, X2, X3, X4)) -> a__U21(mark(X1), X2, X3, X4),
   mark(U22(X1, X2, X3, X4)) -> a__U22(mark(X1), X2, X3, X4),
   mark(U23(X1, X2, X3, X4)) -> a__U23(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__zeros() -> zeros(),
              a__U11(X1, X2) -> U11(X1, X2),
              a__U12(X1, X2) -> U12(X1, X2),
                a__length(X) -> length(X),
      a__U21(X1, X2, X3, X4) -> U21(X1, X2, X3, X4),
      a__U22(X1, X2, X3, X4) -> U22(X1, X2, X3, X4),
      a__U23(X1, X2, X3, X4) -> U23(X1, X2, X3, X4),
             a__take(X1, X2) -> take(X1, X2)}
 Fail