Donn Cave wrote: > Left unexplained is ``true "is-a" relationships''. Sounds > like an implicit contradiction -- you can't implement > something that truly is something else. Without that, and > maybe a more nuanced replacement for "is-implemented-using-a", > I don't see how you could really be sure of the point.
Try this article for an explanation of is-a: http://www.objectmentor.com/resources/articles/lsp.pdf IMO Robert Martin explains what good OO design is better than anyone else. His book "Agile Software Development" is excellent. Kent -- http://mail.python.org/mailman/listinfo/python-list
