TRS: { a__fib(N) -> a__sel(mark(N), a__fib1(s(0()), s(0()))), a__fib1(X, Y) -> cons(mark(X), fib1(Y, add(X, Y))), a__add(0(), X) -> mark(X), a__add(s(X), Y) -> s(a__add(mark(X), mark(Y))), a__sel(0(), cons(X, XS)) -> mark(X), a__sel(s(N), cons(X, XS)) -> a__sel(mark(N), mark(XS)), mark(fib(X)) -> a__fib(mark(X)), mark(sel(X1, X2)) -> a__sel(mark(X1), mark(X2)), mark(fib1(X1, X2)) -> a__fib1(mark(X1), mark(X2)), mark(add(X1, X2)) -> a__add(mark(X1), mark(X2)), mark(s(X)) -> s(mark(X)), mark(0()) -> 0(), mark(cons(X1, X2)) -> cons(mark(X1), X2), a__fib(X) -> fib(X), a__sel(X1, X2) -> sel(X1, X2), a__fib1(X1, X2) -> fib1(X1, X2), a__add(X1, X2) -> add(X1, X2)} Fail