Esprit d'escalier

[pozorvlak]

I was at the Heriot-Watt semigroup day on Friday (at which I was one of a surprising number of category theorists).

It was only after I'd got there that I realised I should have been wearing my No2ID T-shirt...

Comments

[penguinlord8017.livejournal.com]

Although we PenguinLords possess awesome knowledge, we do not yet fully understand your Earth humour. Could you possibly explain the joke for us? And be proud! For 'tis not many who can humble the PenguinLords.

[pozorvlak.livejournal.com]

I was wondering how long it would take someone to ask. Semigroups are mathematical structures like monoids, but which don't necessarily have identity elements.

I didn't say it was a good joke...