I will give an introduction to the Forlan formal language theory toolset, which was designed to facilitate sophisticated experimentation with formal languages. Forlan is embedded in the functional programming language Standard ML, a language whose notation and concepts are similar to those of mathematics. It is strongly typed and interactive, properties that help make experimentation robust, simple and enjoyable. I'll present an extended example of the kind of experimentation that Forlan makes possible. It involves the use of closure properties/algorithms for regular languages/finite automata and a "difference" function on strings of zeros and ones.

http://people.cis.ksu.edu/~stough/
http://people.cis.ksu.edu/~stough/forlan/