Too many ideas, too little time

Last week we had our "Logica e Representatividade" (Logic and Representativeness) meeting on the 14th January 2021, the World Logic Day, almost a week ago  today. The meeting went very well! I was a bit concerned that we had only decided to do it around the 14th December and there was the festive period (between Christmas and New Year's)  in the middle of this month! of course sensible people don't do much during these holidays, so I worried that we would end up without speakers, without discussions and without an audience. and true to the old adage that when in doubt, just produce some slidedeck or two, I spent some lovely panic time doing exactly that.

 

Thank goodness I was wrong in all three accounts: all of our Invited Speakers did show up with some lovely videos, moving histories, clever positioning. The discussions flowed naturally and we had a decent audience on YouTube, I'm told. As I had said in December, the idea was to get the ball rolling, to start the discussions on all kinds of lack of representation in Logic, and we certainly did that. the difficulty will be the next step!

 

But meanwhile I have been thinking about Public Announcement logic (PAL). More precisely about intuitionistic  PAL, as described by Ma, Palmigiano and Sadrzadeh in "Algebraic semantics and model completeness for IntuitionisticPublic Announcement Logic" and by Balbiani and Galmiche's "About intuitionistic public announcement logic". 

 

The reason I've been thinking about it is that I wanted to complete some old work with Natasha Alechina, Michael Mendler and Eike Ritter in "Categorical and Kripke semantics for constructive S4 modal logic".

The issue I want to explore is the relationship between algebraic semantics and frame semantics.