Introduction to Logic

This is, for the most part, a standard introduction to logic textbook. You're completely welcome to use it for self-study, or, if you're a teacher, for a course. I try to make everything as clear, simple, and intuitive as possible while not sacrificing rigor. While most everything in this book is standard, there are two notable things. First are the rules for the quantifiers, drawn from Kit Fine's Arbitrary Objects and adapted to be suitable for an introductory course, which contain both an universal generalization rule and an existential instantiation rule. Second, the final chapter contains a complete presentation of the paraconsistent logic LP, pitched at a completely introductory level. These two things (chapters 9 and 11) might be interesting to you even if you're not the book's intended audience. There is an online site with practice problems and a proof-checker for the natural deduction systems: https://simonelli-logic-lab.ryansim92.chatgpt.site/. If you're using the book for self-study or you're an instructor, you can email me for the answers to the exercises at the end of each chapter at [email protected].