Mastodawn

Alright, future engineers!
**Set Cardinality** is the number of distinct elements in a set.
Ex: For `A = {apple, banana, apple}`, `|A| = 2`.
Pro-Tip: Don't count duplicates! Each element is counted only once.
#DiscreteMath #SetTheory #STEM #StudyNotes

zerology May 11

I'm looking for an intro into set theory for a very non mathematical person. Everything I find uses numbers, sets of sets of sets, and such things.

Did the mathematicians loose their marbles? :-)

I mean, explaining sets using marbles should be an easy way to introduce the concepts. Only if those are understood, it may be sensible to go to Hilberts hotel, Russells paradox, and maybe, just maybe to Cantors diagonal argument.

#math #SetTheory #marbles

Suggestions welcome.

Fish Face May 10

Wasn't expecting a set theory round on university challenge - a gift to all three set theorists who watched the episode!

#maths #settheory

Cardinal Reinhardt May 6

RE: https://friendica.world/display/84b6ef2b-1569-fb6a-c9a4-fc9241315409

This topic is too close to my heart for me to find it funny 😅
#math #mathematics #settheory #infinity

ModernMaslow May 4

RE: https://mastodon.social/@sflorg/116517535576002455

The human behavioral range, filters overlapping data segments by learned, hard encoded, and individual bias...

#BehavioralScience #Scalar #Differential #Equations #DoingTheMath #BehavioralRange #ValueTheory #SetTheory

Christina Richards May 3

Late to the party, but I heart “Rethinking Set Theory”, Tom Leinster’s presentation of ETCS (https://arxiv.org/abs/1212.6543). My natal foundation is higher-order logic, and this is the first time set theory has made any sense to me, other than as a technical device.

Bonus lecture notes: https://webhomes.maths.ed.ac.uk/~tl/ast/ast.pdf

#settheory #etcs #higherorderlogic

Rethinking set theory

Mathematicians manipulate sets with confidence almost every day, rarely making mistakes. Few of us, however, could accurately quote what are often referred to as "the" axioms of set theory. This suggests that we all carry around with us, perhaps subconsciously, a reliable body of operating principles for manipulating sets. What if we were to take some of those principles and adopt them as our axioms instead? The message of this article is that this can be done, in a simple, practical way (due to Lawvere). The resulting axioms are ten thoroughly mundane statements about sets. This is an expository article for a general mathematical readership.

arXiv.org

Cardinal Reinhardt May 2

Oh, I've read a few of these articles individually, but I didn't realise there was a central grouping of the math foundations articles from quanta https://www.quantamagazine.org/series/the-evolving-foundations-of-math/
#math #mathematics #logic #settheory

The Evolving Foundations of Math | Quanta Magazine

An exploration of how mathematicians are still renovating and rebuilding the core pillars of their field today.

Quanta Magazine

Ur Ya'ar Apr 30

הנה אני לפני יומיים, חוגג את פרסום המאמר שלי עם לאטה ווניל ועוגת אוכמניות עם קצפת טבעונית 😋
https://doi.org/10.1016/j.apal.2026.103777

#אקדמיה #מאמר #פרסום #קפה #קפה_ומאפה #תורת_הקבוצות #OpenAccess #academia #SetTheory

Ur Ya'ar Apr 30

Happy to share that my paper "Short sequences of measures in the cofinality-ω constructible model" is now published open-access at the Annals of Pure and Applied Logics

https://doi.org/10.1016/j.apal.2026.103777

#academia #paper #SetTheory #logic #OpenAccess #publication