Weierstrass p

Weierstrass p

In mathematics, the Weierstrass p (℘, or \wp at a larger font size, or ℘ in bold form, or ℘ in italicized form, a stylized letter p), also called pe, is used for the Weierstrass's elliptic function. It is occasionally used for the power set,[1] although for that purpose a cursive capital, rather than lower-case, p is more widespread. It is named after the German mathematician Karl Weierstrass.

Its Unicode code point is U+2118 ℘ script capital p (HTML: ℘ ℘). The naming is incorrect, because it is always a lowercase letter, but this error is not corrected in later versions in order to keep the Unicode standard stable.[2] The TeX code for this character is \wp.

Starting with Unicode 3.0.1 a separate, capital symbol is available for powerset, namely U+1D4AB 𝒫 mathematical script capital p (HTML: 𝒫 ), which is available as 𝒫 in HTML5.[3][4] As of 2009, only a few specialized OpenType fonts support this code point.

References

  1. ^ de Haan, Lex; Koppelaars, Toon (2007), "Chapter 2 — Set Theory: Introduction", Applied Mathematics for Database Professionals, Apress, p. 35, ISBN 978-1-59059-745-3 
  2. ^ "Unicode Technical Note #27: Known Anomalies in Unicode Character Names". Unicode Consortium. 2006-05-08. http://unicode.org/notes/tn27/. Retrieved 2011-06-11. 
  3. ^ "8.5 Named character references — HTML 5". W3.org. http://www.w3.org/TR/html5/named-character-references.html. Retrieved 2010-03-15. 
  4. ^ "Unicode Character 'MATHEMATICAL SCRIPT CAPITAL P' (U+1D4AB)". Fileformat.info. http://www.fileformat.info/info/unicode/char/1d4ab/index.htm. Retrieved 2010-03-15.