Quine Set Theory - next LUW session, September 28 at 4pm CET

[jean-yves beziau]

The next Logica Universalis Webinar  session will take place September 28 at 4pm CET

Speaker:  Tin Adlešic 
Title: A Modern Rigorous Approach to Stratification in NF/NFU
Abstract:  The main feature of NF/NFU is the notion of stratification, which sets it apart from other set theories. We define stratification and prove constructively that every stratified formula has the (unique) least assignment of types. The basic notion of stratification is concerned only with variables, but we extend it to abstraction terms in order to simplify further development. We reflect on nested abstraction terms, proving that they get the expected types. These extensions enable us to check whether some complex formula is stratified without rewriting it in the basic language. We also introduce natural numbers and a variant of the axiom of infinity, in order to precisely introduce type level ordered pairs, which are crucial in simplifying the definitions in the last part of the article. Using these notions we can easily define the sets of ordinal and cardinal numbers, which we show at the end of the article. The same approach can be readily applied to NF.
https://link.springer.com/article/10.1007/s11787-022-00310-y

Chair: Srecko Kovac 
https://www.ifzg.hr/~skovac/index_files/Page328.html
Editorial Board LU

Associate Organization:
European Set Theory Society
https://ests.wordpress.com/trustees-2022-2024/
presented by its president, Philip Welch
https://en.wikipedia.org/wiki/Philip_Welch

This session will take place during the 11th  LAP in Dubrovnik

The LAP series of logica events 

http://imft.ftn.uns.ac.rs/math/cms/LAP2022

will be presented by Zvonimir Šikić.

To take part, register here:

https://www.springer.com/journal/11787/updates/20065848

Jean-Yves Beziau

Organizer of LUW and President of LUA

http://www.logica-universalis.org/LUAD