### 4th Edition Information

This page the release of the 4th edition of the book. The 3rd edition remains available.

After many years of development, I am please to announce that the 4th edition of *Discrete Mathematics: an Open Introduction* is **now available**, here and on Runestone Academy.

The new edition brings many improvements and a new organization of content. In particular, the book now starts with logic and proofs, then practices those proofs with graph theory. The second half of the book contains material on counting (with a new "application to probability" section) and sequences. Over the last few years, I have found that students have more success with this arrangement. There is also a stronger emphasis on discrte structures, which should make the book more useful for students in computer science, while still focusing on understanding mathematical concepts essential for math majors and future math teachers.

There is more interactivity as well. More interactive exercises (which you can give students credit for if you create a course with the book on Runestone Academy; it is completely free for you and your students) and some interactive Sage and Python code to explore some topics.

A PDF of the book is also also available. There will not be a print edition available until next year, when CRC Press will release it. The online version will remain available and free forever, and the book is still released under a Creative Commons License (but note the new Non-Commercial addition to the license).

### License

Discrete Mathematics: an Open Introduction, 4th edition by Oscar Levin is licensed under CC BY-NC-SA 4.0

You are free to download, use, and print as you wish to, for noncommercial purposes. You can also modify the text as much as you like (create a custom edition for your students, for example), as long as you attribute the parts of the text you use to the author and release your modified version under a compatible license.

If you are interested in using parts of the book combined with another text with a similar but different license (GFDL, for example), please reach out to get permission to modify the license.