Good news, logic fans! The Open Logic Project is a project to write an open-source textbook on logic. And if you read it, you’ll find tautologies like the last sentence completely thrilling.
The book is aimed at a non-mathematical audience, mainly computer science and philosophy students, so it assumes very little knowledge of the basics. The project was instigated by Richard Zach, who’s Professor of Philosophy at the University of Calgary. The rest of the project team consists of Aldo Antonelli, Andy Arana, Jeremy Avigad, Gillian Russell, Nicole Wyatt, Audrey Yap, and Richard Zach. They’re aiming to cover first-order logic, sequent calculus, soundness and completeness theorems, computability theory, and incompleteness. If things go well, they want to add material about model theory, computability and Turing machines (that’s already in progress), and some stuff on philosophy of language and mathematics.
A high-quality textbook for free would be pretty good on its own, but what’s really nifty is that the source code has been set up so the book is configurable to your tastes: you can say what kind of notation you’d like, and even adapt theorems and lemmas to use different proof systems.
The Open Logic Project official website
Get the source code and contribute on GitHub
@OpenLogicProj on Twitter
Recognising a good idea when he sees one, William Stein has put the source code to his Springer-published undergraduate textbook Elementary Number Theory: Primes, Congruences, and Secrets: A Computational Approach on GitHub.
The book introduces classical elementary number theory and elliptic curves, with lots of Sage code to encourage you to play around with the structures involved. If you want a physical copy, you can still get one from Springer-Verlag for £29.99.
If you don’t already know Stein, he’s the director of the Sage project to create a viable open source alternative to software such as Mathematica and Maple. At the moment he’s working on cloud.sagemath.com, a browser-based Sage environment hosted in the cloud. I think it’s pretty good!
Get the source code: Elementary Number Theory: Primes, Congruences, and Secrets on GitHub.
Announced by William Stein on Google+.
A chap called Dixon Crews has posted to reddit’s maths section asking for help with a writing project.