Re: U+2118: Script P versus Weiserstrass p

From: Kenneth Whistler (
Date: Mon Nov 15 1999 - 15:34:36 EST


This is old news. The interpretation of U+2118 was fixed in Unicode
3.0 many months ago. The data is available in the UNIDATA directory--
see NamesList.txt. But here is the relevant excerpt:

        = Weierstrass elliptic function
        * actually this has the form of a lowercase calligraphic p, despite its name

And the glyph shown in the Unicode 3.0 charts has the distinctive
calligraphic p form associated with the Weierstrass elliptic function.

This is the reason why MATH SCRIPT CAPITAL P was *not* omitted in
the math alphanumerics proposal -- because U+2118 "SCRIPT CAPITAL P" is
not actually SCRIPT, nor is it CAPITAL.


> Dear Unicode gurus,
> As noted on
> in question 18, Unicode 2.1 confuses and combines as U+2118 the
> potentially very different characters
> My limited exposure to mathematics suggests that while a) and b) might
> well be unified (?), c) is certainly something very different with a
> descender, and the Unicode 2.0 and UCS:1993 example glyph only matches
> meaning c) in contrast to the name of this character.
> It seems that the AMS STIX project <> is already
> very busyly working on deconfusing these in the revision of the math
> aspects of Unicode.
> Was the meaning of U+2118 already somehow clarified in Unicode 3.0?
> Shall a Unicode 3.0 font designer prefer to let U+2118 look like a
> SCRIPT CAPITAL P (for power sets) or like a WEIERSTRASS ELLIPTIC
> FUNCTION symbol?
> >From the ISO proposal on
> I concluded so far that MATH SCRIPT CAPITAL P in plane 1 will not be
> excluded by the already available U+2118 SCRIPT CAPITAL P, so am I right
> in assuming that U+2118 will continue to be associated with the
> Weiserstrass-style glyph found in Unicode 2.0 and UCS:1993?
> Markus
> --
> Markus G. Kuhn, Computer Laboratory, University of Cambridge, UK
> Email: mkuhn at, WWW: <>

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