Category Archives: IFL

Why mandatory reiteration in Fitch-style proofs?

Digressing from issues about the choice of language(s), another post about principles for selecting among natural deduction systems — another choice point, and (though I suppose relatively minor) one not considered by Pelletier and Hazen. Take the most trite of examples. It’s … Continue reading

Posted in IFL, Logic | 7 Comments

Truth trees for propositional logic

I’ve revised (and of course revised again, and re-revised!) the chapters on truth-trees for propositional logic for the second edition of my intro logic text. What took four chapters and forty pages has now become two chapters and twenty-eight pages, … Continue reading

Posted in IFL | 1 Comment

Conditionals, yet again

It’s very predictable, I would imagine, that some of the chapters that have been giving me the most grief as I write the second edition of my logic text are the two chapters where I introduce the material conditional. In the last … Continue reading

Posted in IFL | Leave a comment

Empty domains #1

From wild mathematical universes back to nothing much at all: the question of empty domains in first-order logic. Not that I have anything very insightful to say:  but I want to get my mind clearer before committing myself to a … Continue reading

Posted in IFL, Logic | 10 Comments

The material conditional — analysis or replacement?

Update. I posted a couple of chapters, just 22 pages, hot off the laptop, from a bit later in the draft second edition of my Intro to Formal Logic about the material conditional. I’m now a little unhappy with them, … Continue reading

Posted in IFL, Logic | Leave a comment

Unsatisfying satisficing

There’s no getting away from it. You know perfectly well you can’t try to optimize a book — that way madness lies (or at least, never finishing). You know perfectly well you have to satisfice. But that is oh so … Continue reading

Posted in IFL, Logic | Leave a comment

Intro to Formal Logic 2nd ed. — readers wanted!

It’s not so very often in life that you get a shot at putting right something major, that first time around occupied a lot of time and energy, but didn’t turn out as well as you intended. So I’m grabbing … Continue reading

Posted in IFL, Logic | Leave a comment

Intro to Formal Logic 2nd ed. — help, please!

If you know my Introduction to Formal Logic reasonably well, and in particular if you have at some time taught from it, do please read on! CUP suggested over a couple of months ago now that I write a second … Continue reading

Posted in IFL, Logic | 3 Comments

IFL2: a first instalment

OK, I have been tinkering with the opening chapters of my Introduction to Formal Logic, trying to improve them for the planned second edition. Here then are the early chapters up to and including the first Interlude, in an initial re-draft [updated … Continue reading

Posted in IFL | Leave a comment