[Mike O]

See this link- and type in pronation or you can type in supination
http://medical-dictionary.com/dictionaryresults.php

Donn,
I wouldn't mind discussing this with you, but we will need to work through the terminology and get to your exact question. Pronation/Supination are medical terms for movement of the forearm - that movement doesn't change the wrist condition. That said , it's important to note that in Ben Hogan's paper back book "Five Lessons The Modern Fundamentals of Golf" on page 102 and 103- Hogan used those terms inappropriately in regards to the wrist- arching and bending the wrist would be the general non-medical explanation of those wrist conditions in Hogan's book, NOT pronation and supination. The terms he uses in his book are practically embarrassing- in their lack of regard for the proper medical term.
Mike O.

Edit update: Donn, you are correct that bending the left wrist causes the clubface to close and lay back. But keep in mind, that hinging, specifically angled hinging(closing with layback) is performed with a flat left wrist. So bending the left wrist, producing closing and layback is not the same as a hinging motion.

Back to the medical terms- Homer used the turning and rolling terms because he could apply them at the same time to both forearms. As opposed to pronation and supination- where the left forearm say is supinating while the right forearm does the opposite move of pronation. I believe that you're referring to the lead left forearm, in which case the forearm motion of supination would tend to be a closing only move, while pronation would be a no closing or reverse roll move. But I'm just rambling incoherently now- if you want to repost and clarify, we could continue- otherwise I'll consider the case closed.
Thanks,
Mike