Author Archives: Peter Smith

Raymond Smullyan (1919–2017)

I first came across Raymond Smullyan’s work — surely  like many of my sort of vintage — through his wonderfully inventive and illuminating short(ish) paper “Languages in which self-reference is possible” which was reprinted in Hintikka’s 1969 The Philosophy of Mathematics (in the Oxford Readings series). Still … Continue reading

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Setting tableaux using prooftrees.sty

[Updated] The first edition of IFL was typeset using FrameMaker (long since defunct on a Mac), so I’m having to LaTeX the second edition from scratch. I’m using Clea Rees’s fairly new package prooftrees.sty for downward-branching tableaux, a.k.a. truth-trees, since this seems … Continue reading

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Since it is Schubert’s birthday ….

Barbara Bonney, soprano; David Shifrin, clarinet; André Watts, piano. Der Hirt auf dem Felsen, “The Shepherd on the Rock”, D. 965

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Conditionals again

Here are two draft chapters on conditionals for the second edition of my Introduction to Formal Logic (to replace chapters 14 and 15 of the current edition). I’ve got to the point that I’d very much welcome comments on these. … Continue reading

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Serendipitous distractions

So the CUP Book Sale is over for another twelve months — and with changed rules after last year’s unseemly scrums, this year’s Sale was a very much more enjoyable and civilised affair. After a few pretty abstemious visits, I still came away … Continue reading

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Frege on “if”

I’ve been looking at the passage early in the Begriffsschrift where Frege introduces the material conditional — not, of course, using that label, and not of course with our notation. He notes that can be affirmed when A is denied or when … Continue reading

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Scott Aaronson on P ?= NP

As of course is the way with these things, no sooner had I put online TYL2017 than something appears which I would like to add to the Guide. Scott Aaronson has put together a 120 pages survey article on the … Continue reading

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Tom Leinster’s Basic Category Theory

I just love the opening two sentences of Tom Leinster’s 2014 introductory book, which still seem about as good a minimal sketch of what category theory is up to as you could hope for: Category theory takes a bird’s eye … Continue reading

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Teach Yourself Logic 2017

The Teach Yourself Logic 2016 Study Guide was viewed an astonishing 51K times and download 3K times from my academia.edu page last year. It was also downloaded another 1.4K times from this Logic Matters site. I guess (or at least, hope!) … Continue reading

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The material conditional and the logic textbooks (3)

So turning to Nick Smith’s long and discursive book, what line does he take on the relationship between everyday conditionals and the material conditional? Smith, as usual, sets aside subjunctive conditionals; the issue then is the relation beween indicative conditional … Continue reading

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