Thursday, July 2, 2015

Stanford's Workshop on Logic, Rationality, and Interaction

This isn't my favorite picture of Stanford (the place is very photogenic, it looks beautiful almost always), but it's the one that I associate with the workshops on Logic, Rationality and Interaction. So it's appropriate. Many times I tried to remember something I heard in one of the workshops, so it makes sense to collect at least the programs here.

The first workshop was in 2012. I need to go back to my ideas for “Failure of Interpolation for Intuitionistic Logic of Constant Domains”. I'd like to write it for Grisha. The second workshop was the one where I only managed to go one day, the second one. The third workshop was opened by Chris Potts, now the director of CSLI. This year I was invited speaker, yay!!

Saturday, June 27, 2015

Advice on Constructive Modal Logic

This is a picture of Dana Scott when he wrote "Advice on Modal Logic". The paper is fun (it's from 1970, but not freely available, it seems), the subject is fun and there is an awful lot of more fun things to do with it. One of them is constructive or intuitionistic modal logics. Like Modal Type Theory.

But I am feeling tired of trying to force philosophers and computer scientists to collaborate on the subject. If your friends don't want to talk to your other friends, sometimes you just have to let it go.

At least for a while. Mathematical problems can be like wine or cheese, some are better fresh,  you attack them fiercely and win or lose. Some you need to put away,  to mature (or  not), and hope that the process will improve them.

Together with Charles Stewart and Natasha Alechina, I wrote one more note on that. A very preliminary version is here. And I talked about it in Berkeley's Logic Colloquium in March. Slides are available. For my part, I will concentrate on the  'small picture' now, the details that I think I know do work. Instead of trying to think about why it all hangs together, if  indeed it does.

Frank Pfenning has a lovely slide deck, celebrating Scott's 70th birthday here.

Saturday, June 13, 2015

Plans, plans and expectations

The picture is from Doghousediaries and if I could draw to save my life I would add a few crocodiles to the pond. But I cannot, so the rocks, the ladders and the hail will have to do.

Also the fact that it took me the best part of four hours to find this cartoon again, would be a good indicator that I don't give up easily. yes, I don't.

But sometimes it's good to remind oneself that there is always a different way of doing things and given enough time, I will find it.
Here are slides of a talk I gave in October 2012. The picture is very appropriate.


Sunday, June 7, 2015

Logic Spring at Stanford

Last weekend we had the 4th CSLI Workshop on Logic, Rationality & Intelligent Interaction. (This is Johan van Benthem closing the meeting.)

Johan invited me to talk about logic work on language and, vain that  I am, I could not resist and said yes. and then panicked about what, how, if, etc...

In the end it wasn't the best talk ever, but I think I managed to convey what I want to do and how I intend to do it. At least a bit. Here are the slides, warts and all.

Saturday, May 30, 2015

Relevant Logic Revisited

In 1992 I tried to read Anderson and Belnalp's book `Entailment, Vol. 1: The Logic of Relevance and Necessity' (1976) to help Maria Claudia Mere with her PhD thesis. 

She completed her work `Logicas Relevantes: formalismo e semantica'
in 1993, and I was a bit disappointed with relevant logics. I was hoping for prettier mathematics, cleaner proof-theory and clearer philosophical views. Now that my standards have changed a little, maybe I should re-read this work.

Wednesday, May 27, 2015

Maude for Textual Entailment

This is Maude Fealy, a star of silent movies, and no, I don't mean this Maude, but instead Maude the rewriting system developed by Messeguer and others, first at SRI then at Illinois.

They say in their Maude webpage "Maude is a high-performance reflective language and system supporting both equational and rewriting logic specification and programming for a wide range of applications."

Vivek Nigam and I have thought that it should be easy to use rewriting logic to prove formally entailment and contradiction of formulas arising from text, using the PARC's  Bridge system, as a black box. We wrote a preliminary note, and I talked about it at LSFA 2014.

The note `Towards a Rewriting Framework for Textual Entailment' is available, as are the Maude files used.

Transfer vs. Glue Semantics?

The short version of this post is Glue=principled, based on Linear Logic, Transfer=efficient, based on (linear) Rewriting.

But much, much more can and should be written.

The reason for the post is collect a few references. And to post a new(ish)  paper of Dick Crouch, which shows that Transfer semantics is totally independent of the grammatical theory that it originates from,  Lexical Functional Grammar (LFG). The paper is Transfer Semantics for the Clear Parser, it was presented at Natural Language and Computer Science (NLCS 2014), the workshop I organized with Larry Moss and Christian Retore as part of the Vienna Summer of Logic.

There are also two other papers on Transfer Semantics, these use LFG and the the XLE parser. The  papers can be found in this blog post. One shows how to construct transfer semantics from f-structures, the other how to rewrite transfer semantics into knowledge representation. Now I need to add the references for Glue Semantics.