And of course, evolution of the code with great explanations - http://www.michaelnielsen.org/ddi/lisp-as-the-maxwells-equations-of-software/ http://www.michaeln

And of course, evolution of the code with great explanations - http://www.michaelnielsen.org/ddi/lisp-as-the-maxwells-equations-of-software/ http://www.michaelnielsen.org/ddi/lisp-as-the-maxwells-equat... . Particularly good is (canonical?) lisp-in-lisp code at the end.