Christian Lawson-Perfect @christianp@mathstodon.xyz

Omg it draws TeX! #plotter

I've had a couple of days off work because I was BURNT. OUT.

For some reason, I've remade my old wordsearch generator in Elm, using Glitch. Once I worked out how to use elm reactor to show the nice compilation errors, it was a lovely experience!

https://wordsearch-generator.glitch.me

Charles Babbage fact: the What's the Difference Engine, designed during his blue period, accepts input represented by the positions of brass cogs.
On turning a crank, the machine emits a protracted sighing noise. There is no other output.

I've spent another couple of hours playing with Lean, following @XenaProject's Formalising Mathematics course (https://github.com/ImperialCollegeLondon/formalising-mathematics)
I think the hardest part for me is remembering what each notation really represents, like ¬ P is really (P → false)

Teachers don't want you to learn this trick!!!

To get 99% of something, first increase it by 10%, then decrease it by 10%.

It really works!!!!!

Writing another chapter of my memoir, "I tried to do the maths, and now here we are"

Tooting this because I want to do it but don't have time, and I want someone to pester me about it in a few weeks' time:

I'd like to start a collection of mathematical notation ambiguities, inconsistencies, and unpleasantness. It'd be a wiki, or at least collaboratively edited

Or, less esoterically, when I've got a subscripted variable followed by a number, e.g.

x₂4

(I will not accept "put the 4 first" as an answer)

Time for another round of "when is it OK to omit the multiplication symbol?"

I think for powers of numbers, it's fine to omit, e.g.

2²3² = 36.

What about subscripts, commonly used to show the base of the representation, e.g.

12₅23₅ = 331₅,

or do I need a multiplication symbol:

12₅ × 23₅ = 331₅.

π can stand for a variety of things in maths, but is 3.14159... the only constant it's conventionally used for?

Found a new integer sequence but it looks so stupid I don't think I'll submit it

I've worked out how to write an Elm app on Glitch!
Here's a minimal example: https://elm-lang.glitch.me/

And here's a more complicated app: https://gaussian-origami.glitch.me/

Write the digit 1 eight million, one hundred and seventy seven thousand, two hundred and seven times in a row.

That's a prime number.

Discovered by Ryan Propper and Serge Batalov a few days ago. https://oeis.org/A004023