Normalization Generics (NFx, NFKx, NFxy)

[Zach Lym]

> What does that quoted statement mean?  I'm having a hard job working
> out what the meaning of full case folding is.  I'm not having any
> doubts about the meaning of toCasefold(NFD(X)), so there is no issue
> for 'canonical caseless matching'.

The "case folding is closed under canonical normalization" or the other part?

Closed as in closure: https://en.wikipedia.org/wiki/Closure_(mathematics)

Refer to page 240 of the standard, Chaper 5 "Implementation
Guidelines" Section 18 "Case Mappings":

http://www.unicode.org/versions/latest/ch05.pdf