Grudgingly over the years, I’ve more or less made my peace with the use of “fun” as an adjective. “That was a fun movie.” You get the idea.

Mathematicians often speak of “toy problems,” meaning problems cooked up to help one explore this or that phenomenon in the simplest possible setting. Yesterday a well-known mathematician spoke to me of certain problems that were “toyer” than others, and even of one that was the “toyest” of all. This may take me a few more years of grudging work.

[19 May 2025]