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# Ben Reiniger@bmreiniger@mathstodon.xyz

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@jordyd
"...now lastly, set $x=10$, ..."

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that if a finite poset has a unique maximal $x$, then $x$ is maximum.

If not, there is a $y_1||x$. $y_1$ is not maximal, so there is $y_2>y_1$; we cannot have $y_2<x$, else transitivity would give $y_1<x$, and we cannot have $y_2>x$ because $x$ is maximal, so $y_2||x$. Continuing, we build a chain $y_1<y_2<\dotsb$ (with $y_i||x$ for all $i$), contradicting finiteness.

(This proof also suggests a construction of an infinite poset without the property.)

Ben Reiniger boosted

Update/expansion of my intro last year. I'm now going into fourth year maths rather than theoretical physics, having switched degrees. (That's assuming I pass some exams this week that I deferred due to illness).

I brew beer as a hobby, and code when I have spare time. I enjoy writing science fiction, but I'm a long way away from publishing anything.

I have 111 characters spare so: My favourite equation is $\int_M \mathrm{d}\omega = \int_{\partial M}\omega$

Ben Reiniger boosted

Hi guys, I'm an engineer who lives in Paris and I'm very interested in mathematics. I would like to revisit all the math basics starting from university (classes prepas for the frenchies out there ).
Thank you all for your warm welcome.

Ben Reiniger boosted

Ben Reiniger boosted

Hey everyone! I am a math grad student just finishing up my prelims and moving into the realm of research. I nerd out with everything to do with computers and foundations of math stuff and pretty much all things algebraic.

Also I am learning to sail and it's awesome. Nothing like getting out on the water. Highly recommended.

Ben Reiniger boosted

the sequence is exact!

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Ben Reiniger boosted

The mate-in-n problem of infinite chess is decidable
Article by Brumleve, Dan and Hamkins, Joel David and Schlicht, Philipp
In collections: Puzzles, Games to play with friends
Infinite chess is chess played on an infinite edgeless chessboard. The familiar chess pieces move about according to their usual chess rules, and each player strives to place the...
URL: arxiv.org/abs/1201.5597
PDF: arxiv.org/pdf/1201.5597v4

Ben Reiniger boosted

hi mathstodon! i'm devin. i'm a math phd student (with under a month to go until my defense!), so this instance seemed like a nice fit. i study neural networks and some math biology, but i also really like combinatorics, as well as many things that are not math. let's follow each other if you want!!

Ben Reiniger boosted

@kosinus Castling.club is really fun! Is the source code available online? Also, I have a couple suggestions for useful features:
- resignation
- draw offers
- takeback offers
- PGN export (copying and pasting the move list is almost good enough but it would be really convenient to get PGN with the player names filled in, etc

If the source is available I'd be happy to implement any of these and send you a PR. Thanks for making this!

Ben Reiniger boosted

3Blue1Brown on slicing cones to make ellipses: youtube.com/watch?v=pQa_tWZmlG

Highly recommend a watch!

Ben Reiniger boosted

@EmpressZo thinking vaguely about doing something like thatsmathematics.com/mathgen/, but with (i) more interesting structure in the generating grammar (like parametrizing over the symbols used so there's some notational consistency) and (ii) notation/sentence patterns drawn from doing some NLP on actual published papers. probably in Haskell, plus Python for the NLP part

Ben Reiniger boosted

I'm going to start measuring the complexity of coding tasks in coffee cups: 'This was a five-espresso algorithm.'

Ben Reiniger boosted

Can anyone recommend books to learn more about data science and analytics (statistics, math, computer science)? I've been considering it as a career to go into, and I would like to learn as much as I can about it.

Ben Reiniger boosted
Ben Reiniger boosted

I'm running a four-round instant knock-out tournament throughout the month of July to basically squeeze a load of fun maths out of my friends. Let's see if we can make it all come together! Voting starts on the 1st of July.
aperiodical.com/2018/06/announ

Ben Reiniger boosted

Some merging tessellations I drew/constructed

Ben Reiniger boosted

340. THE CUBIC KNIGHT'S TOUR. Some few years ago I happened to read somewhere that Abnit Vandermonde,
a clever mathematician, who was born in 1736 and died in 1793, had devoted a good deal of study to the question of knight's tours. Beyond what may be gathered from a few fragmentary references, I am not aware of the exact nature or results of his investigations, but one thing attracted my attention, and that was the statement that he had proposed (1/2)

...then right for the feels:
"... I really hope he continues to teach, graph theory has been one of my all time favorite courses at IIT and I think it would be a shame if Professor Reiniger never taught again. His handwriting was pretty good for a math professor." 2/2

Course evaluation:
"Reiniger is great. I liked him right away because I could tell he really loved graphs and he was real excited to teach us all. He was super knowledgeable and could answer almost any question on the spot which I thought was really cool of him. He was really good at coming up with simple examples and counter examples to remember certain properties..." 1/2

Anybody have a go-to data science / machine learning resource?