Mark Dominus on Nostr: I was very surprised to learn that this isn't universally known among ...

I was very surprised to learn that this isn't universally known among nonmathematicians. I had a discussion about this with a bright, well-educated person a couple of years ago, and had to bring out the example of the primality of 1, which has historically changed, to demonstrate that I wasn't papering over some complexity or lack of consensus.