mrychlik's blog

In the Spring of 2015 I taught a course on Applied Combinatorics, using a superb book by Alan Tucker.
You will find the outline of the course by following this link:

Combinatorial Mathematics

Over the past few years, I neglected the content of this website somewhat. So many things to do, so little time. But in part this was due to the hard time that the chosen CMS, Drupal, was giving me. Yesterday I moved the Website to Drupal 7, and things appear to work better. For a math website, it is a must to have formulas. The package DruTeX has become obsolete, and the current rendering is done using MathJAX, which is both more secure (rendering of TeX happens in user's browser) and more reliable way to render random formulas, such as this one:

My Groebner basis and Comprehensive Groebner packages needed a little dusting. I have authored two software packages in this area:

• An extension to the Computer Algebra System Maxima, which provides for Grobner basis calculations. The package contains a demo file which illustrates its usage.
• A standalone package for calculating Comprehensive Groebner Systems, called CGBLisp. Comprehensive Groebner bases allow one to answer questions about systems of parametric equations with parameters.

The packages will be available at my development site at:

The software link: Click here.

I wrote a program several year ago for the purpose of edification of my students, which produces step-by-step solutions to linear systems using Gaussian elimination. The core of the program was written in Lisp (one of my favorite programming languages) but the Web interface was done in Perl. In recent days, I rewrote the program completely and entirely in Lisp. If you are a Lisper, you may be interested in the fact that the matrix can be entered in either MATLAB or Lisp syntax, thanks to the Lisp reader hooks.

In recent days I grappled with the issue of choosing the CMS. This amounts to the "Joomla vs. Drupal" contest, it appears. These are the two most popular CMS of today.