A non-converging LaTeX document
Today, I wrote this LaTeΧ document. It only uses default LaTeΧ functionality, and uses no packages.
If you compile it (twice so that cross references are not ??s), you will get a four page document (pages numbered i to iv), that repeatedly says: "This document ends on page v."
If you then recompile it, you will get a five page document (pages numbered i to v), that repeatedly says: "This document ends on page iv."
Repeatedly compiling it will alternately give these two results, and so the process of compiling this LaTeX document does not converge.
Christmas (2020) is over
Christmas card 2020
Christmas (2020) is coming!
Comments in green were written by me. Comments in blue were not written by me.