Innmoot

This might be the last of the recent spate; if I don't write as much I'll have more time to do things rather than explaining comments I provoked :) But this was a really nice evening.

I nearly didn't make it, but abandoned work at seven and cycled down to the CTS start of term innmoot at the Castle. The people I probably know *best* weren't there, but there were a lot of people, including Nick and Chess who only rarely make it these days but it was very nice to see, who I have now known for a quite a long time, and just about everyone there is lovely and interesting and easy to talk to, and I'd forgotten how nice the CTS crowd could be, when most of them I don't see elsewhere.

There was cuddling, and discussion of politics and glossolalia and immigration and housebuying and more Tim K. Top Secret LOTR plays :) and two different dinner parties plotted :) and a full termcard all but one event and a Sibbleying and a scrap of paper listing amusing/important things to look up and do, now transcribed. About the only thing missing was maths puns!

I didn't drink anything -- still being slightly spaced/hyper from lack of sleep after port last night -- but those had the same effect; I only worry I might have been slightly too manic at the start and too quiet at the end[1] :)

I was going to get to bet *early* but I should still get nine hours sleep and get up at a usual time, so tomorrow should be productive.

[1] OK, ok, A, I *am* you-know-who :)

Koalas are inherently funny

Find your own pose!

A *simple* maths problem.

Q. Show that *=N⁴+N²+2N is a multiple of 4.
A. It's a multiple of N so changing N by four doesn't change the expression being a multiple of four or not[1]. So we only need to check N=0,1,2 and 3. But it works for those cases or you wouldn't have asked the question. QED.

Full credit? You would, I think, normally accept four one-line substitutions as sufficient? You don't actually write out the multiplications, you just say "1⁴+1²+2.1=4", and you could do the same in modular arithmetic and all the answers would be zero. And this is just a completely trivial collapse of that.

It's even realistic -- if you're proving S(n) for all n and find that S(n)∀n<N=>S(n)∀n [2] someone's probably crunched through N on a supercomputer already[3], and it each m must be S as if m wasn't they'd have published, the pleasure of a paper titled "Hahahahah!" and reading in its entirity "~S(m)" :)

But something about the answer bothers me. I think it's that (a) it's a smartarse and (b) a good habit to be into is to at least note down each case and put a tick by it to show you've tried them all in your head and didn't forget one.

[1] Yes, I could have used modular arithmetic language, but the colloqiual language fits the point better.
[2] Googling for "html math symbols" first produces a page suggesting you use the symbol font :(
[3] OK, professional problems are complicated enough that m might be too stupidly big. Witness the colouring theorem. But it's a major major major major[4] step, and someone else will hopefully fill in the blanks, even if they turn out to be hard.
[4] C22 reference.

Talking to mum and further todo list mods

Hey, that was lovely. I chatted to mum for absolutely ages. And in a strange reversal I spent half an hour telling her about everything going on in my life, and she spent three quaters of an hour telling me about her architecture and its untrackdownable bug :)

I've just restreamlined my todo lists slightly. Now, things from all todo lists and diary get funneled into a short today "today" section stored at the top of the most used one. It's working well again.

Last eclectic poll

My name is and:
I read livejournal, even if I rarely post.
I remember what 14² is without calculating it.
Wow, you've been busy this week.
You should stop messing with your own polls and use LJ.
You should stop messing with LJ and write your own blogging system.
My great-aunt wrote blogging software, you insensitive bastard!

ETA: Oh. That last textbox was supposed to read "*****" but it didn't work.