Peter Smith's Blog, page 142

Blowing the dust off LaTeX for Logicians

The LaTeX for Logicians pages have been woefully ignored of late. But at last — as a bit occupational therapy while my brain is still in a jet-lagged mush — I've started moving the pages to this site, updating content a little as I go. Using Wordpress as a content management system should make it quite a bit easier to maintain the pages in the future.

The relevant pages now also have their very own — hopefully memorable — web-address, www.latexforlogicians.net. This address ought to remain...

Haaparanta and Kunen

Not too much serious work has got done the last couple of weeks, what with touristy visits and finishing Christchurch teaching. But I have been dipping into two recent books.

Leila Haaparanta's The Development of Modern Logic (OUP 2009, weighing in just under a thousand pages) is a curious tome. Eighteen essays by various hands, of widely varying lengths and widely varying depth. There's a sixty seven page essay on "Late Medieval Logic" and just seven pages on "Gottlob Frege and the Interplay ...

Postcard from Arrowtown

We spent Easter doing the touristy thing of driving down to Queenstown and taking the coach/boat trip to Milford Sound. Just beautiful. Less wildly dramatic but in its way as beautiful was the drive on from Queenstown to Wanaka over the hills above Arrowtown (which lies in the valley in the photo). I think we've fallen in love with the South Island.

Gödel Without (Too Many) Tears — the whole story!

Just to say that all eleven handouts for my short course at UC Christchurch are now online here. These should serve as an introduction to the first three quarters of my Introduction. (Many thanks to David Makinson for catching some typos and for some suggested improvements in episodes 1 to 9.)

Eat New Zealand

This won't be of interest to too many, but for NZ foodies …

We were beginning to lose hope. The quality of ingredients available here in NZ can be amazing: even our local New World supermarket (think Tesco's) has local cheese and fish of just stunning quality. The local farmers' markets are even better.  So why, we were wondering, are the local restaurants so very, very average (or, mostly, worse)?

But we've now had two terrific meals in three days. In Wellington we ate on the waterfront at

More Gödel, less Parsons, no LaTeX

The first nine episodes of the revised Gödel Without (Too Many) Tears are now online here. (Two more to come next week, and a closing review in a twelfth episode thereafter.)

But my plan to work through Parsons again here has unfortunately had to be shelved as a result of other New Zealand excitements. Though I do still hope to have something more useful to say about Parsons's claims about induction and impredicativity in particular.

And, prompted by a couple of emails, I'm vividly aware that ...

Postcard from Taieri Gorge

Took the train trip from Dunedin up the Tiaeri Gorge to Middlemarch and back. Simply beautiful as you can see.

Of the town, however, we only really saw central Dunedin. Some rather splendid early buildings mixed in with too much later grot in a rather depressing way: and even the good buildings tend to have appalling street level shop frontages pasted on. The central Octagon is awful. Why on earth don't they thoroughly pedestrianize it and then get rid of the shabby fourth rate bars and pubs t...

Postcard from Dunedin

In Dunedin to read a paper at the University of Otago philosophy department. I was rehashing the line about Church's Thesis taken in the last chapter from my Gödel book (and I don't feel too guilty about talking about something published a few years ago now, as comments can still affect how I treat matters in the second edition of the book). I'd worried a bit in advance of giving this talk in Christchurch and Otago that the first half — about the general idea of a squeezing argument and...

How to think about consciousness?

Keith Frankish — via his eminently followable twitterings — got me reading Brian Fiala, Adam Arico and Shaun Nichols: "On the psychological origins of dualism: Dual-process cognition and the explanatory gap."

Highly interesting, enjoyably written, and — on an admittedly quick and casual read — pretty persuasive. But the question whether they are exactly right  is in some ways less interesting  for me than the question "Is this a good sort of approach to diagnosing what is going on with some...

Kleene's Normal Form Theorem entails Gödel's First Incompleteness Theorem

Talking about this result at a maths seminar, I realized my previous effort at this in the book is less pretty than it should be. In effect, I stupidly embedded (i) a proof that  not every partial recursive function is potentially recursive in Church's sense into (ii) the proof of incompleteness. They should of course be neatly separated. So here (in under two pages) is how.

And comments or notes of typos/thinkos will be welcome!