Can NFKC turn valid UAX 31 identifiers into non-identifiers?

Hans Åberg via Unicode unicode at
Thu Jun 7 05:41:55 CDT 2018

Now that the distinction is possible, it is recommended to do that.

My original question was directed to the OP, whether it is deliberate.

And they are confusables only to those not accustomed to it.

> On 7 Jun 2018, at 12:05, Philippe Verdy <verdy_p at> wrote:
> In my opinion the usual constant is most often shown as  "��" (curly serifs, slightly slanted) in mathematical articles and books (and in TeX), but rarely as "π" (sans-serif).
> There's a tradition of using handwriting for this symbol on backboards (not always with serifs, but still often slanted). A notation with the "π" symbol uses a legacy troundtrip mapping for old OEM charsets on low-resolution text terminals where it was distinguished from the more common Greek letter which was enhanced for better readability once old low-resolution terminals were replaced. "π" looks too much like an Hangul letter or a legacy box-drawing character and in fact difficult to recognize as the pi constant, but it may still be found in some plain-text paragraphs of inline mathematical formulas on screens (for programmers), at low resolution or with small font sizes, where most text is in sans-serif Latin and not slanted/italicized and not using an handwritten style.
> If you think about writing a functional programming language using inline formulas, then  the "π" symbol may be ok for the constant, and custom identifiers for a function would use standard Greek letters (or other standard scripts for human languages), or would use "pi" in Latin. You would then write "pi(π)" in that inline formula. For a classic 2D mathematical layout, you would use  "pi(��)" with distinctive but homonegeous styles for custom variables/function names and for the classic mathematical constant.
> As much as possible you will avoid mixing confusive letters/symbols in that language.
> Confusion is still possible is you use old texts mixing old Greek letters for numerals: you would in that case avoid using the Greek letter pi for naming your custom function, and would reserve the pi letter for the wellknown constant. But applying distinctive styles will enhance your formulas for readability.

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