Outdated egg!
This is an egg for CHICKEN 4, the unsupported old release. You're almost certainly looking for the CHICKEN 5 version of this egg, if it exists.
If it does not exist, there may be equivalent functionality provided by another egg; have a look at the egg index. Otherwise, please consider porting this egg to the current version of CHICKEN.
banterpixra takes a BNF-style syntax description and generates SVG syntax diagrams from it. It's documented more fully at http://www.kitten-technologies.co.uk/project.php?project=banterpixra.