Thank you Alex, for getting the thread back into line. I was getting nervous when the discussion centred around V squared and 1/V squared, perfectly good at lower altitudes, but not above Mcrit, and, to reitterate my own words from my earlier post, "This is the region where Jet aeroplanes spend most of their time". (Above Mcrit)
As for discussion relating to Vmd's incorporation into the various formulae, there are a great number of high flying "Business Jet" type aircraft where Mcrit is BELOW Vmd defined by the low speed polars, and Minimum Drag speed is then defined by Mach Number, now we have to consider Mmd (Mach Number for minimum drag, i.e. flying on the "back" side of the conventional drag curve defined by EAS, but nevertheless at minimum total drag as defined by EAS and Mach Number).
One more spanner to throw into the works.
Regards,
Old Smokey