The Textbook Blog

This is a location for discussion of Symbolic Logic. Comments may range from general assessment to details of presentation. We can discuss substantive questions about logic too. You may submit a post of your own or add comments to another. If you require special symbols, \LaTeX code may be inserted between the markers [latex] . . . [/latex] — to start with this, see LaTeX Typing (you see the compiled result only when posted).

Make a Post

version updates

9/10/19: The SL version number is updated from 8.1 to 8.2.  Main structure remains the same.  But there are enough changes to mark this as a substantive improvement over previous versions.

4/29/19: The SL version number is incremented from 8.0 to 8.1. Changes to the main body are minor. The primary update is that Answers to Selected Exercises are moved online. This permits large pages and so improved formatting.


jolly good

As a retired engineer, I decided to get back to my passion of understanding ethics. Most of the works were clearly woolly and very soon I realized that I needed to enhance my skills in logic to make any headway in this direction. Most of the recent books in logic were loaded in formal mathematics and appeared way beyond my reach. It was then that Prof Roy’s book on the Internet came as a pleasant surprise. Two years later, I managed to complete most of the exercises in his book and understand the principles. It is to Prof Roy’s credit that someone like me with little training in formal mathematics can learn such a difficult subject and all along keep my interest in it without being daunted by the complexity of the subject. During this journey, Prof Roy gave his time unstintingly to respond to my queries. Nuggets of Russelian wit, veiled challenges to the daredevils, and his love for his family are sprinkled in every chapter in this book. What attracted me most were the problems at the end of each chapter; in every chapter you invariably find one which asks the student to draft a short note explaining the main ideas in the chapter in a language his teenage daughter can understand. It is well known that, if you understand something well, you ought to be able to communicate that to the non-initiated. And, equally if you teach someone what you learnt, your concepts become even clearer. As the Tamil poet says, knowledge is rare commodity that grows by giving. To recognize this and challenge the reader to try his hands at this, Prof Roy shows great intuition in the art of teaching.

As an old man living in the UK, I cannot say his book is cool, but perhaps I could say it is jolly good.  R.V.

answers to exercises

I have complete answers to nearly all the exercises in the text (and am working on the rest). It is easy to move answers in or out of the Selected Answers at the back of the book. Short of including them all, if you think some answer(s) should or should not be included among the Selected Answers, let me know. T.R.