An open symbolic logic project that includes a textbook, sample problems, and an interactive proof testing system.
Category: PHIL 210
forallx: An Introduction to Formal Logic (Magnus, 2017) (CC BY-SA)
A Concise Introduction to Logic (DeLancey, 2017) (CC BY-NC-SA)
Modern Formal Logic Primer (Teller, 1989) (Copyrighted, Free for Instructional and Educational Use)