You are fortunate that @zenvelo & @LuckyGuy are tolerant souls. Demonstrably is just a short way of saying “can be demonstrated.” The fascinating thing about dealing with your questions and answers is that I can never decide whether or not you are deliberately stringing us out. I will tell you frankly, that if this is the case, you’re the best I’ve ever seen at it. Initially, when I read this question, I took it that you were pulling my leg in a variation of “who’s on first?”, which is actually the way my conversations with you always read. I really cannot decide whether you have the genius to co-opt us into Abbots opposing your Costello. But if you ever want an example of the “demonstrably obtuse”, have a glance at this thread. Anyway, I once again sit here confused; not wanting to hurt your feelings, but on the other hand, unwilling to allow genius to float past unacknowledged.