Aaron is teaching our intro logic course (“Logic I”) this term, and as part of a pilot project to redesign that course (which also includes partially “flipping” it), we’ve also adapted P. D. Magnus’s open textbook forall x. To be more precise, we’ve remixed a remix by Tim Button of P.D. Magnus’ textbook with some material from J. Rob Loftis’s remix plus some material from Tim Button’s Metatheory and then added our own material and revisions. (Aaron previously wrote about how we decided on these changes.) Thanks to Creative Common open licensing, we can do this: just shamelessly take other people’s work and make it work for us, without paying them. In this case, the license is CC BY-SA, which requires only that we give credit (the “BY” part) and that we make the end product available under the same terms (the “SA”) part.

In order to keep track of our changes, I’ve put our remix as well as PDM’s original and TB’s remix on GitHub. (JRB maintains his own GitHub repository of the Lorain County remix/expanded “Open Introduction to Logic”.) is So if you want to start your own remix and also want to use Git, you can start from any of the four version by forking the respective repository.

Here’s a rundown of the most important changes, with links to the corresponding Git commits where you can see what’s changed.

We put some material from PDM’s original version back into TB’s version (b3b6f97).

We added some material from JRL’s remix, mainly a discussion of soundness and completeness and many exercises (09b6d3a) and glossary entries (3f1276c).

We added a chapter on normal forms and truth-functional completeness from TB’s Metatheory (f49b6b3) and make it independent of the rest of that book (0721158)

We moved the chapter on natural deduction for TFL to before the FOL part.

We made a whole bunch of smaller stylistic changes, e.g., change all I’s to we’s, shall’s to will’s, change some examples to make them less reliant on a US or British background, etc. (fd9b99e, f091b03, 2a95058), added a preface (afd969d), glossary entries for the part on FOL (367d614), as well as some changes to terminology (ffa6567).

Changed the typography and layout to match the Sets, Logic, Computation layout and to fit on Crown Quarto paper for printing at lulu.com.

You can see a complete line-by-line comparison on GitHub.

You can download the final product if you don’t want to compile it yourself, and you can even buy a printed copy if you want!

Warning: We have not done anything with the solutions yet, so those do not match the numbering in the book and in fact might not match the exercises themselves!