Here’s a detail from my genealogy. (This image is a link to a pdf file of the entire thing.)
Teaching started for first semester, with the launch of Logic: Language and Information 1 on Coursera. That’s been a lot of fun already, with over 17,000 enrolled. There’s something very exciting about being involved with a large number of students all around the world, choosing to work hard to learn logic for the first time.
Rembember that you are dust, and to dust you shall return.
What is negation?
One answer you find in the literature is that negation is the operator that makes each instance of the Law of the Excluded Middle (LEM) and the Law of Non-Contradiction (LNC) turn out to be true. That is, every sentence of the form \[ p\lor \neg p \qquad \neg(p\land\neg p) \] is true, no matter what sentence we use in the place of \(p\) (where \(\neg\) stands for negation, \(\lor\) for disjunction, and \(\land\) for conjunction).
This is the wrong way to try to define negation. If you read on, I’ll explain why.
I’ve used DuckDuckGo, which has a comprehensive index of this place, and which can be styled to match the visual treatment of the rest of the site. Please let me know if there are any problems with the implementation.
I’m Greg Restall, and this is my personal website. I teach philosophy and logic as Professor of Philosophy at the University of Melbourne. ¶ Start at the home page of this site—a compendium of recent additions around here—and go from there to learn more about who I am and what I do. ¶ This is my personal site on the web. Nothing here is in any way endorsed by the University of Melbourne.