This is the Mississippi State version of forallx. It covers truth-functional logic and introduces first-order logic.
A paperback version is available here.
This book is based on a text written by P. D. Magnus and then revised and expanded by Tim Button, J. Robert Loftis, Aaron Thomas-Bolduc, and Richard Zach. It has been further revised for the 1000-level logic course at Mississippi State University.
This textbook is licensed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license.