I had a discussion with one of my students, who was convinced that they could prove something was countable using Cantor's diagonal argument. They were referring to (what I know as) Cantor's pairing function, where one snakes through a table by enumerating all finite diagonals, e.g. to prove the countability of $\Bbb N\times\Bbb N$. In the same way one proves that $\Bbb Q$ is countable.

I was therefore very surprised to learn that this application of the pairing function is titled "Cantor's first diagonal argument" on the [German Wikipedia](https://de.wikipedia.org/wiki/Cantors_erstes_Diagonalargument). Is this title for Cantor's proof of the countability of $\Bbb Q$ in any way *standard* (in German), i.e., is it mentioned by this title in any literature outside of the German Wikipedia?