My website abstractmath.org (http://www.abstractmath.org/) has reached the status of beta.  It is intended for students who are in the early stages of learning some kind of math that involves abstraction, as well as their teachers.  Members of this group may be particularly interested in the chapters Understanding Math (http://www.abstractmath.org/MM/MMUnderstandingMath.htm) and Doing Math (http://www.abstractmath.org/MM/MMDoingMath.htm).

This is the way textbooks should be written. 

A new version of the abstractmath.org article on Variables and Substitution.

A greatly enlarged version of the abstractmath.org article on mathematical structures.

My website abstractmath.org (http://www.abstractmath.org/) has reached the status of beta.  The site is intended for students who are in the early stages of learning some kind of math that involves abstraction, as well as their teachers.  It also has some discussion of mathematical English and the symbolic language of math.

Math information in the internet age, part I

For the last few months I have been systematically going through the abstractmath.org articles, revising and updating them. This post lists the more important revisions.

This is a thorough revision of an old post in Gyre&Gimble. It provides many diagrams, some of them manipulable using Wolfram CFD files, to help students to understand Riemann sums.