Generic functions and business rules support systems

PEAK-Rules is a highly-extensible framework for creating and using generic
functions, from the very simple to the very complex. Out of the box, it
supports multiple-dispatch on positional arguments using tuples of types,
full predicate dispatch using strings containing Python expressions, and
CLOS-like method combining. (But the framework allows you to mix and match
dispatch engines and custom method combinations, if you need or want to.)