What is forallx?
forallx is an open-source elementary logic textbook. It provides introductions to:

• Truth-Functional Logic (aka Propositional Logic)
• Truth-tables and associated semantic concepts
• First-Order Logic (aka Predicate Calculus)
• Interpretations of FOL, and associated semantic concepts
• Natural deduction for both TFL and FOL, and associated proof-theoretic concepts

P.D. Magnus was the original author of forallx. In an extreme act of generosity, Magnus released the textbook under a Creative Commons licence. You can find Magnus's version of the textbook here.

Tim Button modified forallx for a logic module he ran at the University of Cambridge. You can find Button's version of the textbook here.

I have further modified Button's version of forallx for the University of York's introductory logic module, Reason & Argument​, and I release it here under the same Creative Commons licence as Magnus.

Accessing forallx:York
You can download the PDFs of the textbook and solution booklet here:

• forallx:York (PDF)
• Solution Booklet for forallx:York (PDF)

If you would like to further edit the textbook or the solution booklet, you can download the LaTeX source code here:

• forallx:York (source code)
• Solution Booklet for forallx:York (source code)

If you have any accessibility related difficulties, please do not hesitate to get in touch with me at [email protected].

Going beyond forallx
I have written a series of short logic primers, which are designed to build on the semantics and natural deduction systems presented in forallx:York:

• A Modal Logic Primer
• A Second-Order Logic Primer
• An Intuitionistic Logic Primer

Tim Button has also written a metatheory textbook which follows on from his version of forallx, which you can access here.