Next session of PTS Seminar Series: Maria Osório Costa, October 26, 12pm (UTC+0)

[PTS Network]

Dear PTS-People,

After the summer break, we'll be soon resuming the PTS Seminar Series! This is to announce the next session and speaker, so save the date:

 

- Monday, October 26, 12pm (UTC+0): Maria Osório Costa (University of Lisbon; University College London) will present her work with the title "Bilateral Proofs and Refutations".

 

Here is the abstract:

 

Logical bilateralism challenges the traditional concepts of logic by treating assertion and denial as independent, yet opposed, acts. While inizially devised to justify classical logic, its constructive variants show that both acts admit intuitionistic interpretations. In this talk, we develop this perspective by introducing a logic of incompatible proofs and refutations, BPR. The central idea is that, although proofs and refutations constitute distinct forms of constructive evidence, in some settings, such as mathematical reasoning, they should be incompatible: no statement should be both proved and refuted.

Building on a natural-deduction presentation of BPR, we develop a bilateral sequent calculus and establish cut elimination, the subformula property, and consistency. We then explore BPR using base-extension semantics, establishing soundness and completeness and providing a purely semantic proof of the incompatibility between proofs and refutations. We conclude by discussing how the relationship between Wansing's 2Int and BPR mirrors that between Nelson's N4 and N3, and how BPR captures Nelson's intended behaviour of constructive negation.

 

Please make sure to convert the time correctly to your specific time zone! The talk will take place at 12pm in the UK, 1pm CET, 9pm in Japan, 8am in New York, 9am Brasilia Time (to give just some examples).

 

 

We will send the Zoom link over this list on the day before the session.

All the best,
Sara Ayhan, Hermógenes Oliveira, Antonio Piccolomini d'Aragona and Will Stafford