https://math.stackexchange.com/questions/414036/rationals-and-irrationals-on-the-real-number-line/ is not very well-posed, but all the answers seemed to interpret it the same way: prove that for every two irrationals $i_1 < i_2$, there is a rational $i_1 < r < i_2$. It attracted three different answers, all upvoted.
The question itself has been downvoted and closed, and now I see that it has two votes to delete. If it were deleted, the answers would be lost, which I think would be unfortunate. What can be done to prevent this?
