Thanks. Yes, I see where you are coming from - and i agree. I will certainly put these thoughts to him. I'm pretty confident he'll be delighted to respond. I will keep this thread updated re the outcome.
As an aside, HP invited SME (some years ago) to provide an explanation of the topic. Ever the gentlemen, they gave this careful consideration. They concluded that (at that time) they lacked the expertise to convert their primarily mathematically-based know-how into something that might be of value to the lay person. That sort of candour, it seems to us, is in shorter supply these days than hitherto.
Thanks again - Neil