The box is not silly but unnecessary and distracting The box is already too long you have to scroll to see the whole list and it has a potential to get longer certainly This kind of the box is only useful and necessary in cases like  the article is separated into several pages because the article would be too long if those were in one page  The article is about one entity among several ones There is no much relationship between real and natural numbers except they are numbers You want me to convince you then can I also ask you to convince me first To my knowledge there was no consensus about having such a box In other words I am just reverting the article to what it used to be and see if we can have concensus or something