[imakecomments]

Chapter 1 is completely trivial to anyone with mathematics training. It makes no difference to me if the author expands upon the section or not. It doesn't hurt my demographics of readership because we wouldn't read that section anyways. You know who would read it? The 'practitioner'. Someone that hasn't seen a matrix since high school or freshman year of college.

The interviews the authors give paint the picture this book is for the 'practitioner'. If Chapter 1 is meant for a brief review then don't advertise the book for a complete practitioner/beginner. Either make the book for the practitioner or not. If you do, then don't pretend to serve introductory math in it that the unfamiliarized reader will read and understand. They fail at their purpose there. So either make that chapter useful for the practitioner or leave it out and assume the mathematicians already know it. Maybe put it in an appendix and let us get to the meat quicker. It honestly does not take much time to define what a matrix is, give an example, define matrix multiplication, give examples etc. Same applies with basic definition and examples of derivatives. These are mindless mechanical procedures anyone can learn. It wouldn't take too much extra space to include some thoughtful examples. Maybe I should write an 'introductory group theory' textbook and start discussing geometric group theory 2 pages in if we want to get into not serving an intended audience's purpose.

I like what the author's are doing. I'm on their side, but I'm making suggestions that could serve a wider audience.