*forall x: Calgary* is a full-featured textbook on formal logic. It covers key notions of logic such as consequence and validity of arguments, the syntax of truth-functional propositional logic TFL and truth-table semantics, the syntax of first-order (predicate) logic FOL with identity (first-order interpretations), translating (formalizing) English in TFL and FOL, and Fitch-style natural deduction proof systems for both TFL and FOL. It also deals with some advanced topics such as modal logic, soundness, and functional completeness. Exercises with solutions are available. It is provided in PDF (for screen reading, printing, and a special version for dyslexics) and in LaTeX source code.

A proof editor/checker for the proof system used is available at proofs.openlogicproject.org. However, instructors wishing to adopt it should consider the open-source Carnap system, which supports the notation and proof systems of *forall x: Calgary*. Check out the sample exercises for the book on carnap.io.

There are translations into German (forall *x*: Dortmund) and Portuguese (Para Tod*x*s: Natal).

You can download PDFs of the **most current version under development** here:

`forallxyyc.pdf`

(in color, for screen reading)`forallxyyc-accessible.pdf`

(an accessible version for dyslexics)`forallxyyc-print.pdf`

(b/w, for printing on Quarto stock)`forallxyyc-letter.pdf`

(b/w, for printing on regular letter-size paper)`forallxyyc-solutions.pdf`

(solutions booklet)

**Note that these files change whenever the source files change.** So if you use the text in a course, better to download the PDFs and make them available to students directly, rather than to link here, to avoid mismatches between versions.

PDFs of the **Fall 2020** edition are archived here:

`forallxyyc-f20.pdf`

`forallxyyc-accessible-f20.pdf`

`forallxyyc-print-f20.pdf`

`forallxyyc-letter-f20.pdf`

`forallxyyc-solutions-f20.pdf`

If you’d like to purchase a nice paperback copy of the Fall 2021 edition, you can do so on Amazon (US | CA | UK | DE | AU), or use search in your local Amazon store. Be sure to get the latest version that’s available in print (Fall 2021). The version on Amazon usually is not as current as the PDF.

(The process for getting the book printed is described here and here.)

Clone the GitHub repository locally or download the ZIP file and run LaTeX on one of

`forallxyyc.tex`

(in color, for screen reading)`forallxyyc-accessible.tex`

(accessible version)`forallxyyc-print.tex`

(b/w, for printing on Quarto stock)`forallxyyc-letter.tex`

(b/w, for printing on regular letter-size paper)

You’ll have to run `makeglossaries`

to produce the glossary as well.

To make changes to the definitions in the preamble and `forallyyc.sty`

file, put them in a file named `forallxyyc-local.sty`

. For instance, to get the connectives to be ∼, &, ⊃, ≡ instead of ¬, ∧, →, ↔︎, and atomic formulas *Lab* instead of *L(a,b)*, copy `forallxyyc-local-sample.sty`

to that file.

*forall x: Calgary* is based on *forall x: Cambridge*, by Tim Button used under a CC BY 4.0 license, which is based in turn on *forall x*, by P.D. Magnus used under a CC BY 4.0 license, and was remixed, revised, & expanded by Aaron Thomas-Bolduc & Richard Zach. It includes additional material from *forall x* by P.D. Magnus and *Metatheory* by Tim Button, both used under a CC BY 4.0 license, from *forall x: Lorain County Remix*, by Cathal Woods and J. Robert Loftis, used with permission, and *A Modal Logic Primer* by Robert Trueman, used with permission.

This work is licensed under a Creative Commons Attribution 4.0 International License.

The LaTeX source code for this work is available on GitHub at github.com/rzach/forallx-yyc.