leonardopacheco - Network

A short note I wrote a few months ago just got published: https://www.kurims.kyoto-u.ac.jp/~kyodo/kokyuroku/contents/pdf/2293-06.pdfI show...

A short note I wrote a few months ago just got published: https://www.kurims.kyoto-u.ac.jp/~kyodo/kokyuroku/contents/pdf/2293-06.pdf

I show that diamonds are already embedded in Artemov and Protopopescu's intuitionistic epistemic logic (they are just double negations).

This is part of some work I'm doing to understand diamonds in intuitionistic modal logics.

#Logic #ModalLogic

Just gave a talk in at Nagoya University on an intuitionistic version of GL (and a cyclic proof system for it). Slides here:...

Just gave a talk in at Nagoya University on an intuitionistic version of GL (and a cyclic proof system for it). Slides here: https://leonardopacheco.xyz/slides/prooftheory2024.pdf

#Logic

New job, new #introductionI'm Leonardo Pacheco, and I work on mathematical #logic. I just started a position at the Institute of Science...

New job, new #introduction

I'm Leonardo Pacheco, and I work on mathematical #logic. I just started a position at the Institute of Science Tokyo (old Tokyo Institute of Technology) under the supervision of Ryo Kashima.

Currently I'm researching non-classical modal logics. Two topics I'm particularly interested are the expressivity of fixed-point operators and non-classical versions of GL.

Does anyone know of a nice introduction to topological semantics of first-order intuitionistic logic?(I've searched but didn't find...

Does anyone know of a nice introduction to topological semantics of first-order intuitionistic logic?

(I've searched but didn't find anything good, maybe I'm using the wrong keywords.)

#Logic

I'm on my way to Advances in Modal Logic 2024, in Prague. Looking forward to quite a lot of the presentations.

I'm on my way to Advances in Modal Logic 2024, in Prague. Looking forward to quite a lot of the presentations.

Maybe I can finish the paper by next month? If there is no problem in the proof it should be fine.

Maybe I can finish the paper by next month? If there is no problem in the proof it should be fine.

Oops, looks a sentence from one of my papers under review is better as a whole new paper (and out of the old paper).

Oops, looks a sentence from one of my papers under review is better as a whole new paper (and out of the old paper).

I created a new account to post about non-work things: https://wandering.shop/@lp

I created a new account to post about non-work things: https://wandering.shop/@lp

It's effectively summer, so it's time to listen to summer songs.

It's effectively summer, so it's time to listen to summer songs.

I've been skimming Troelstra and van Dalen's book on intuitionistic logic. Just found out about the Rieger--Nishimura lattice, which...

I've been skimming Troelstra and van Dalen's book on intuitionistic logic. Just found out about the Rieger--Nishimura lattice, which classifies all the one-variable intuitionistic formulas w.r.t. provability. (Picture from Wikipedia.)

I wonder if there's an analogous lattice for intuitionistic modal logics too.

#logic

In the middle of all of that I also had lots of presentations/events. Looking forward to May and June, where I'll stay in Vienna and...

In the middle of all of that I also had lots of presentations/events. Looking forward to May and June, where I'll stay in Vienna and write some (a lot of?) things down.

So the beginning of this year was quite busy. A few highlights:- I presented a paper on the mu-calculus at Fixed Points in Computer Science,...

So the beginning of this year was quite busy. A few highlights:

- I presented a paper on the mu-calculus at Fixed Points in Computer Science, at Naples. I showed that with multiple modalities satisfying quite strong conditions, we can express more complicated properties using more fixed-points; this is in contrast with unimodal S5, where fixed-points express no new properties.
See the paper here: https://www.irif.fr/_media/users/saurin/fics2024/pre-proceedings/fics-2024-pacheco.pdf

- I got a paper accepted on CiE. I'll present it this summer. Here I talk about higher-order feedback Turing machines; machines which can access oracles with halting information of computations of the same type. I've also presented about them at CCR at Nagoya; sides here: https://leonardopacheco.xyz/slides/ccr2024.pdf

- I gave two presentations on ongoing work in intuitionistic modal logic, in Japan. The more complete slides are here: https://leonardopacheco.xyz/slides/tokyotech2024.pdf

- I also have two papers under review, probably will receive the reviews soon. And also two short papers that should be finished by summer.

#logic

rantI'm reading a book, why does it have to delete it automatically?

rant

I'm reading a book, why does it have to delete it automatically?

Does anyone have a #recommendation for ebook readers on iOS?Apple Books is just unusable without internet.

Does anyone have a #recommendation for ebook readers on iOS?
Apple Books is just unusable without internet.

Oh, I just got conference invitation spam in Chinese for the first time.

Oh, I just got conference invitation spam in Chinese for the first time.

Note to self:\(\Box\) — L — konieczność\(\Diamond\) — M — możliwość#ModalLogic #Logic

Note to self:

\(\Box\) — L — konieczność
\(\Diamond\) — M — możliwość

#ModalLogic #Logic

It snowed quite a lot today.

It snowed quite a lot today.

Toshiyasu Arai just put a preprint with a pretty big result in arxiv: "In this paper we give an ordinal analysis of a set theory with...

Toshiyasu Arai just put a preprint with a pretty big result in arxiv: "In this paper we give an ordinal analysis of a set theory with \(\Pi_N\)-Collection."

If right, he found the proof-theoretical ordinal of second-order arithmetic.

Link: https://arxiv.org/pdf/2311.12459.pdf

#Logic #ProofTheory

After years in Japan, it feels very weird to be merry-christmas'd. Especially that it is still November! (Even in Brazil it would be way...

After years in Japan, it feels very weird to be merry-christmas'd. Especially that it is still November! (Even in Brazil it would be way too early)

Scheduling emails to send the other day is nice, but who sends an email at 8:00 exactly? Nothing ever happens during round minutes.

Scheduling emails to send the other day is nice, but who sends an email at 8:00 exactly? Nothing ever happens during round minutes.