On Wed, Apr 02, 2014 at 08:01:52PM -0400, John C Klensin wrote: > (and others that should know better), is pretty clearly not tea > but it is less clear whether it is not-tea or not. There is evidently an opportunity for an intuitionistic state machine here. In intuitionism, as I'm sure everyone is fully aware, the law of excluded middle and double-negation are both rejected as axioms (mostly because of the principle of constructive provability. Intuitionism is not a 2-value logic, and may not be a finite-value logic). I think it would be fun to write ABNF for this system. Or more exactly, I think it would be fun if someone else did that. Best regards, A -- Andrew Sullivan ajs@xxxxxxxxxxxxxxxxxx