That would imply that the possession of one trait implies the removal of another. Now, you're starting to talk Prolog-style levels of compiler knowledge. While this wouldn't necessarily be a bad thing, and would be implemented in the definition of the trait, I can see how this would be quite reasonably construed as some serious action-at-a-distance ...
We are the carpenters and bricklayers of the Information Age.
Then there are Damian modules.... *sigh* ... that's not about being less-lazy -- that's about being on some really good drugs -- you know, there is no spoon. - flyingmoose
I shouldn't have to say this, but any code, unless otherwise stated, is untested