Allow repeated modifiers to simplify naming

[Enivex]

For a handful of symbols, it would be useful to be able to repeat modifiers. I give two examples here.

1. We currently have

× - times
⊗ - times.o

Another variant that has not been named yet is ⨷, where times.o.o is an obvious name candidate.

2. In "Supplemental Mathematical Operators" one finds ⪓ and ⪔.

Natural names would be lt.seq.gt.seq and gt.seq.lt.seq.

(Or any of a number of other alternatives, but they all share the need to repeat one or more modifiers)

This is only somewhat orthogonal to making it possible to disambiguate using order (the other proposal)