Saturday, June 28, 2008

Galois connections again

For some reason, I found myself minded to spend a bit of time tidying up the pages on posets and Galois connections that I was working on some weeks ago. They have the form of the first two chapters of something longer, something that may or may not get written -- but these pages should have some stand-alone interest. Here's the new version. As always, comments gratefully received. (Thanks so far to Tim Button and Luca Incurvati -- and in particular to Nathan Bowler who gave a talk in which he explained the basic idea of syntax/semantics as a Galois connection, which inspired me to write these pages.)

[Later: Monday 30th June] And that link is now to a better version, with some paragraphs about quantifiers as adjunctions, and some superfluous material removed for later use.

1 comment:

Shawn said...

Excellent! I've been presenting some stuff from Dunn's book on gaggles to some people around Pittsburgh. I have been using the earlier version of the handout to illustrate a concrete instance of Galois connections, as concrete as classes of models and of sentences are, and it has been extremely helpful.