Michael Kinyon
@profkinyon.bsky.social
Mathematics professor at the University of Denver. Quasigroups, Semigroups, Automated Deduction. He/Him. Occasionally drop in at Mathstodon, but not as much as I used to.
I hope my coauthor shares my optimism.
November 22, 2025 at 7:02 PM
I hope my coauthor shares my optimism.
At one of those "clarity vs elegance" junctures in my writing of this paper. I'm greedy though, so I hope I'll figure out how to have both.
November 21, 2025 at 9:01 PM
At one of those "clarity vs elegance" junctures in my writing of this paper. I'm greedy though, so I hope I'll figure out how to have both.
While considering a purchase, I asked "how much does the free trial cost?" so now I have to walk from Denver into the Pacific Ocean.
November 20, 2025 at 8:18 PM
While considering a purchase, I asked "how much does the free trial cost?" so now I have to walk from Denver into the Pacific Ocean.
Reading a paper that denotes the kernel of a mapping f by
"ker f" but the kernel of a mapping n is denoted by "kern".
"ker f" but the kernel of a mapping n is denoted by "kern".
November 18, 2025 at 5:53 PM
Reading a paper that denotes the kernel of a mapping f by
"ker f" but the kernel of a mapping n is denoted by "kern".
"ker f" but the kernel of a mapping n is denoted by "kern".
K: Have you considered consulting a doctor about that?
Me: I am a doctor. I have a PhD in mathematics
K: No, I meant
Me: and therefore I am an expert in all scientific disciplines
Me: I am a doctor. I have a PhD in mathematics
K: No, I meant
Me: and therefore I am an expert in all scientific disciplines
November 14, 2025 at 5:56 PM
K: Have you considered consulting a doctor about that?
Me: I am a doctor. I have a PhD in mathematics
K: No, I meant
Me: and therefore I am an expert in all scientific disciplines
Me: I am a doctor. I have a PhD in mathematics
K: No, I meant
Me: and therefore I am an expert in all scientific disciplines
You kids and your six trig functions. Back in my day we had only one, and we used it for everything.
sin(θ)
sin(π/2 - θ)
sin(θ)/sin(π/2 - θ)
1/sin(θ)
1/sin(π/2 - θ)
sin(π/2 - θ)/sin(θ)
sin(θ)
sin(π/2 - θ)
sin(θ)/sin(π/2 - θ)
1/sin(θ)
1/sin(π/2 - θ)
sin(π/2 - θ)/sin(θ)
November 7, 2025 at 12:15 AM
You kids and your six trig functions. Back in my day we had only one, and we used it for everything.
sin(θ)
sin(π/2 - θ)
sin(θ)/sin(π/2 - θ)
1/sin(θ)
1/sin(π/2 - θ)
sin(π/2 - θ)/sin(θ)
sin(θ)
sin(π/2 - θ)
sin(θ)/sin(π/2 - θ)
1/sin(θ)
1/sin(π/2 - θ)
sin(π/2 - θ)/sin(θ)
a∈A
{a}⊆A
{a}∈𝒫(A)
*sigh*
{a}⊆A
{a}∈𝒫(A)
*sigh*
November 4, 2025 at 3:39 AM
a∈A
{a}⊆A
{a}∈𝒫(A)
*sigh*
{a}⊆A
{a}∈𝒫(A)
*sigh*
I've been in academia for about 33 years, but even today when I hear or read "P.I.", my brain first thinks of Tom Selleck.
November 2, 2025 at 1:15 AM
I've been in academia for about 33 years, but even today when I hear or read "P.I.", my brain first thinks of Tom Selleck.
Our dog freaks out whenever she hears the doorbell.
Trick-or-treating in this neighborhood starts soon.
It's going to be an interesting evening.
Trick-or-treating in this neighborhood starts soon.
It's going to be an interesting evening.
October 31, 2025 at 11:15 PM
Our dog freaks out whenever she hears the doorbell.
Trick-or-treating in this neighborhood starts soon.
It's going to be an interesting evening.
Trick-or-treating in this neighborhood starts soon.
It's going to be an interesting evening.
Reposted by Michael Kinyon
arxiv.org/abs/2510.19961
/Loops with squares in two nuclei/
Michael Kinyon (@profkinyon.bsky.social) , J.D. Phillips
/Loops with squares in two nuclei/
Michael Kinyon (@profkinyon.bsky.social) , J.D. Phillips
October 24, 2025 at 3:27 AM
arxiv.org/abs/2510.19961
/Loops with squares in two nuclei/
Michael Kinyon (@profkinyon.bsky.social) , J.D. Phillips
/Loops with squares in two nuclei/
Michael Kinyon (@profkinyon.bsky.social) , J.D. Phillips
The more coauthors a paper has, the more typos it will have.
It seems counterintuitive but each author assumes the others are the ones responsible for carefully checking everything.
It seems counterintuitive but each author assumes the others are the ones responsible for carefully checking everything.
October 22, 2025 at 5:04 PM
The more coauthors a paper has, the more typos it will have.
It seems counterintuitive but each author assumes the others are the ones responsible for carefully checking everything.
It seems counterintuitive but each author assumes the others are the ones responsible for carefully checking everything.
Abel's line "it appears to me that this theorem admits exceptions" is one of my favorite sentences in the history of mathematics.
Working on the TRIUMPHS project on Abel and Cauchy's approaches to infinite series with my real analysis honors student. We have decided that Abel is totally a hater. #MathSky
digitalcommons.ursinus.edu/triumphs_ana...
digitalcommons.ursinus.edu/triumphs_ana...
Abel and Cauchy on a Rigorous Approach to Infinite Series
By Dave Ruch, Published on 01/01/17
digitalcommons.ursinus.edu
October 21, 2025 at 8:29 PM
Abel's line "it appears to me that this theorem admits exceptions" is one of my favorite sentences in the history of mathematics.
Given a ladder, if:
* you know how to get on the first step, and
* if you're on a step, you know how to get on the next one,
then you know how to climb the ladder. #induction
* you know how to get on the first step, and
* if you're on a step, you know how to get on the next one,
then you know how to climb the ladder. #induction
October 21, 2025 at 3:00 PM
Given a ladder, if:
* you know how to get on the first step, and
* if you're on a step, you know how to get on the next one,
then you know how to climb the ladder. #induction
* you know how to get on the first step, and
* if you're on a step, you know how to get on the next one,
then you know how to climb the ladder. #induction
Me: Canvas is down! How will I teach my class?
K: You hardly use Canvas at all and you never use it in the classroom, so what difference does it make?
Me: I guess I'll cancel class and go hiking.
K: But...
Me: SEE YOU LATER, I'M TAKING THE DOG WITH ME
K: You hardly use Canvas at all and you never use it in the classroom, so what difference does it make?
Me: I guess I'll cancel class and go hiking.
K: But...
Me: SEE YOU LATER, I'M TAKING THE DOG WITH ME
October 20, 2025 at 6:54 PM
Me: Canvas is down! How will I teach my class?
K: You hardly use Canvas at all and you never use it in the classroom, so what difference does it make?
Me: I guess I'll cancel class and go hiking.
K: But...
Me: SEE YOU LATER, I'M TAKING THE DOG WITH ME
K: You hardly use Canvas at all and you never use it in the classroom, so what difference does it make?
Me: I guess I'll cancel class and go hiking.
K: But...
Me: SEE YOU LATER, I'M TAKING THE DOG WITH ME
Inserting a paragraph break in the middle of a sentence because I like to live wild and free, and I want to see if my coauthor notices.
October 19, 2025 at 5:33 PM
Inserting a paragraph break in the middle of a sentence because I like to live wild and free, and I want to see if my coauthor notices.
Coauthor: OK, so that means these elements lie in the subset A.
Me: Do they tell the truth outside the subset A?
C: ... Why do I even talk to you?
Me: I don't know
Me: Do they tell the truth outside the subset A?
C: ... Why do I even talk to you?
Me: I don't know
October 17, 2025 at 5:14 PM
Coauthor: OK, so that means these elements lie in the subset A.
Me: Do they tell the truth outside the subset A?
C: ... Why do I even talk to you?
Me: I don't know
Me: Do they tell the truth outside the subset A?
C: ... Why do I even talk to you?
Me: I don't know
I don't have a learning style but I am definitely a visual forgetter.
October 16, 2025 at 3:14 PM
I don't have a learning style but I am definitely a visual forgetter.
Found at the end of a proof in this manuscript I've been working on:
"... we have the desi red result."
No lie, for a little over a half minute, I puzzled over what I could have possibly meant by "desi red".
"... we have the desi red result."
No lie, for a little over a half minute, I puzzled over what I could have possibly meant by "desi red".
October 16, 2025 at 3:33 AM
Found at the end of a proof in this manuscript I've been working on:
"... we have the desi red result."
No lie, for a little over a half minute, I puzzled over what I could have possibly meant by "desi red".
"... we have the desi red result."
No lie, for a little over a half minute, I puzzled over what I could have possibly meant by "desi red".
Concluding \begin{itemize} with \end{enumerate} like the buffoon that I am.
October 14, 2025 at 11:32 PM
Concluding \begin{itemize} with \end{enumerate} like the buffoon that I am.
Integration by vibes is the best technique
October 13, 2025 at 4:10 PM
Integration by vibes is the best technique
Remembering a professor who, in all sincerity, advised me, a grad student, that if you don't start a journal at some point in your career, you haven't succeeded.
Even at that point in my nascent career, I realized the guy was full of shit.
Even at that point in my nascent career, I realized the guy was full of shit.
October 12, 2025 at 9:21 PM
Remembering a professor who, in all sincerity, advised me, a grad student, that if you don't start a journal at some point in your career, you haven't succeeded.
Even at that point in my nascent career, I realized the guy was full of shit.
Even at that point in my nascent career, I realized the guy was full of shit.
Me: In this problem, if you're not sure what properties of the integers you're allowed to assume, just ask me.
Student: Can I assume Fermat's Last Theorem?
Me: Is that going to help you in some way?
S: Well, no, I just wondered if I can assume it anyway.
Me: 🙄
Student: Can I assume Fermat's Last Theorem?
Me: Is that going to help you in some way?
S: Well, no, I just wondered if I can assume it anyway.
Me: 🙄
October 10, 2025 at 11:08 PM
Me: In this problem, if you're not sure what properties of the integers you're allowed to assume, just ask me.
Student: Can I assume Fermat's Last Theorem?
Me: Is that going to help you in some way?
S: Well, no, I just wondered if I can assume it anyway.
Me: 🙄
Student: Can I assume Fermat's Last Theorem?
Me: Is that going to help you in some way?
S: Well, no, I just wondered if I can assume it anyway.
Me: 🙄
I just learned a little bit about iatromathematics and now I feel like I should lie down for a little while.
en.wikipedia.org/wiki/Iatroma...
en.wikipedia.org/wiki/Iatroma...
Iatromathematicians - Wikipedia
en.wikipedia.org
October 10, 2025 at 9:32 PM
I just learned a little bit about iatromathematics and now I feel like I should lie down for a little while.
en.wikipedia.org/wiki/Iatroma...
en.wikipedia.org/wiki/Iatroma...
@timhenke.bsky.social How's your ã? One of my closest friends is a João and it took me a lot of practice to get his name right.
October 9, 2025 at 8:21 PM
@timhenke.bsky.social How's your ã? One of my closest friends is a João and it took me a lot of practice to get his name right.
Maybe my students will pay more attention if I have my class autotuned
October 8, 2025 at 5:37 PM
Maybe my students will pay more attention if I have my class autotuned