Ned,
> It is more than just the 5 operations above; see also the attached.
These 5 operations are from the Section 9
"Operations required in all flavours"
of the Part 1 "General Requirements".
Your attachment mentions other operations:
mulRevToPair(x,y)
less(a,b)
precedes(a,b)
strictLess(a,b)
strictPrecedes(a,b)
intervalToExact(x)
exactToInterval(x) .
They are from the subsection 10.4 "Reqiured operations"
of the Part 2 "Set-Based Intervals". So they are not required in all flavors.
A flavor doesn't need to contain these operations.
> One of the goals is to keep the basic standard as simple as possible.
> This is from the PAR I submitted to IEEE
Yes. Drawback of making your basic standard the flavor is its complication by 5 operation.
Advantage is making it the flavour is that we avoid misleading situation of two competing interval standards.
-Dima