TRS:
 {                a__from(X) -> cons(mark(X), from(s(X))),
        a__head(cons(X, XS)) -> mark(X),
         a__2nd(cons(X, XS)) -> a__head(mark(XS)),
            a__take(0(), XS) -> nil(),
  a__take(s(N), cons(X, XS)) -> cons(mark(X), take(N, XS)),
    a__sel(0(), cons(X, XS)) -> mark(X),
   a__sel(s(N), cons(X, XS)) -> a__sel(mark(N), mark(XS)),
               mark(from(X)) -> a__from(mark(X)),
               mark(head(X)) -> a__head(mark(X)),
                mark(2nd(X)) -> a__2nd(mark(X)),
          mark(take(X1, X2)) -> a__take(mark(X1), mark(X2)),
           mark(sel(X1, X2)) -> a__sel(mark(X1), mark(X2)),
          mark(cons(X1, X2)) -> cons(mark(X1), X2),
                  mark(s(X)) -> s(mark(X)),
                   mark(0()) -> 0(),
                 mark(nil()) -> nil(),
                  a__from(X) -> from(X),
                  a__head(X) -> head(X),
                   a__2nd(X) -> 2nd(X),
             a__take(X1, X2) -> take(X1, X2),
              a__sel(X1, X2) -> sel(X1, X2)}
 Fail