forall x: Calgary. An Introduction to Formal Logic

P. D. Magnus    Tim Button    Robert Trueman    Richard Zach

Fall 2023 (2023-09-18)

With contributions by J. Robert Loftis and Aaron Thomas-Bolduc

This book is based on forallx: Cambridge, by Tim Button (University College London), used under a CC BY 4.0 license, which is based in turn on forallx, by P.D. Magnus (University at Albany, State University of New York), used under a CC BY 4.0 license, and was remixed, revised, & expanded by Aaron Thomas-Bolduc & Richard Zach (University of Calgary). It includes additional material from forallx by P. D. Magnus and Metatheory by Tim Button, used under a CC BY 4.0 license, from forallx: Lorain County Remix, by Cathal Woods and J. Robert Loftis, and from A Modal Logic Primer by Robert Trueman, used with permission.

This work is licensed under a Creative Commons Attribution 4.0 license. You are free to copy and redistribute the material in any medium or format, and remix, transform, and build upon the material for any purpose, even commercially, under the following terms:

  • You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

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The source for this book is available on Github at and in PDF and HTML format at This version is revision 1d85cb8 (2023-09-18).

The preparation of this textbook was made possible by a grant from the Taylor Institute for Teaching and Learning.

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