- From: <Justus-bulk@Piater.name>
- Date: Thu, 26 Jun 2008 19:11:35 +0200
- To: dev-tech-mathml@lists.mozilla.org, www-math@w3.org

Hi - I'm slightly confused about proper markup and rendering of primes. The W3C appears to recommend that primes be marked up as superscripts, as shown in the subject line. This gave the expected results in Mozilla back when I still used the LaTeX XFT fonts. That's normal: The glyph used for the prime, codepoint U+0030 in cmsy10.ttf, is an oversized, vertically roughly centered slab that is scaled and shifted into just the right position and size by virtue of the superscript. However, Unicode fonts these days provide a glyph (at U+2032) that is quite evidently designed to be used without superscripting; its position and size correspond to apostrophes and quotation marks. Using the above markup, it is thus rendered too small and too high above the baseline. (To see what I mean, point your out-of-the-box, STIXBeta-powered Firefox3 to http://www.w3.org/Math/testsuite/mml2-testsuite/Topics/Primes/primes1.xml and compare the first x-prime to its sample rendering.) So there is, I think, a contradiction between the recommended MathML markup and the reality of glyphs. As far as solutions are concerned, I think that W. Hammond's suggestion (http://www.albany.edu/~hammond/gellmu/primeaccents2.xhtml#mi) has its merits. But if we stand by the <msup/> convention, then MathML renderers will have to treat superscripted primes differently than other superscripted characters. Justus

Received on Friday, 27 June 2008 13:36:18 UTC