I maintain that, with the possible exception of math majors and philosophy majors (and maybe not even in those cases), undergraduates are better served by a serious course in inductive logic than they are by a course in deductive logic. (And I mean a real course in introductory inductive logic, not a critical thinking course.) There are at least a few inductive logic textbooks that are suitable. I like this one: Argument & Inference: An Introduction to Inductive Logic.
That said, I do like teaching symbolic logic, and sometimes there are reasons for doing so. In the past, I’ve used Allen & Hand’s Logic Primer. In the fall of 2019, however, I taught two online sections of intro to logic, and, since the Logic Primer isn’t a great choice for an online course, I started looking for a new textbook that included software. I found Graham Leach-Krouse’s Carnap software package, which is free and is used online. (There’s nothing to download.) Graham has made his software compatible with the systems in several textbooks (Kalish and Montague’s Logic, Bergmann and Moore’s Logic Book, Hardegree’s Modal Logic, P.D. Magnus’ Forallx, and Forallx: The Calgary Remix). I chose Forallx: The Calgary Remix, which, after some revisions, became Forallx: The Mississippi State edition.
Since the course that I was teaching was an online, 100-level course, I decided to only go through truth tables and propositional logic (plus some introductory material). I removed chapters that I wouldn’t need, and I added further explanation to many of the chapters that I kept—in particular, with a eye toward explaining the material to online students. I also added a few sections on using Carnap, and I made sure that the proofs in Forallx matched the format used in Carnap. (Both use the Fitch notation, but, for instance, Carnap uses ‘PR’ and ‘AS’ to cite premises and assumptions, and so I have those in the proofs in Forallx.)
I began the course with the first chapter and one of the appendices from Argument & Inference (An Introduction to Arguments and section A.1 in A Brief Introduction to Deductive Logic). The aim there was to get students as familiar as possible with arguments and the concept of validity. Then, for the remaining eleven weeks of the course, we used chapters 3 – 6, 8 – 11, and 14 – 17 in Forallx.
I am still working on Forallx: the Mississippi State edition, and so every once in a while it gets revisions and improvements. Anyone can use it, and if you would like to see a course outline or need advice on using Carnap, feel free to contact me. I can’t post or distribute copies of the chapters in Argument & Inference, but if you can a copy of the book, you can make copies for your students.