Helen,

Thanks for your reply.

Please be assured that the basic numeric requirements and
limitations of my app have been well explored and understood
by me for some time.

My app in question has been in development, in various
forms (TP > D1 > D3) for many years.

Floating point work is the essential foundation of my app,
and while there are, I'm sure still nuances beyond my ken,
the essentials are in order.

Your further references are greatly appreciated and I will
make use of them.

Thanks again!