- From: Karl Tomlinson <w3@karlt.net>
- Date: Fri, 11 Jan 2008 16:02:02 +1300
- To: www-math@w3.org

There appear to be a few differences between the updated set of entity definitions http://www.w3.org/2003/entities/2007doc/overview.html#diff-xhtml1 and UTR #25 http://www.unicode.org/reports/tr25/tr25-9.html I notice that several mathematical bracket entities have changed from using CJK punctuation character to new mathematical characters, consistent with UTR recommendation here: http://www.unicode.org/reports/tr25/tr25-9.html#_TocDelimiters However there appear to be a few similar entities that have not been changed. lang, LeftAngleBracket, langle still refer to U+2329, and rang, RightAngleBracket, rangle to U+232A. "U+2329 LEFT-POINTING ANGLE BRACKET and U+232A RIGHT-POINTING ANGLE BRACKET, are now deprecated for use with mathematics because their canonical equivalence to CJK angle brackets is likely to result in unintended spacing problems when used in mathematical formulae." "Unicode 3.2 added two new mathematical angle bracket characters (U+27E8 and U+27E9) that are unequivocally intended for mathematical use." http://www.unicode.org/reports/tr25/tr25-9.html#_Toc25 OverParenthesis, UnderParenthesis, OverBrace, UnderBrace still use CJK compatibility forms U+FE35 to U+FE39, but there are now mathematical forms available. U+23DC TOP PARENTHESIS U+23DD BOTTOM PARENTHESIS U+23DE TOP CURLY BRACKET U+23DF BOTTOM CURLY BRACKET What do lbbrk and rbbrk (left/right broken bracket) represent? Are they plain tortoise shell brackets or filled tortoise shell brackets or something else? The updated entity definitions have changed these from CJK punctuation characters U+3014 LEFT TORTOISE SHELL BRACKET and U+3015 RIGHT TORTOISE SHELL BRACKET (which are usually unfilled?) to U+2997 LEFT BLACK TORTOISE SHELL BRACKET and U+2998 RIGHT BLACK TORTOISE SHELL BRACKET (which are wider). "For ordinary tortoise-shell brackets, the use of U+2772 LIGHT LEFT TORTOISE SHELL BRACKET ORNAMENT and U+2773 LIGHT RIGHT TORTOISE SHELL BRACKET ORNAMENT is recommended for mathematical use." jmath has been changed to U+0237 LATIN SMALL LETTER DOTLESS J (as there was no dotless j before Unicode 4.1). Is there a reason why U+1D6A5 MATHEMATICAL ITALIC SMALL DOTLESS J was not used? "the Unicode Standard provides the explicitly dotless characters U+1D6A4 MATHEMATICAL ITALIC DOTLESS I and U+1D6A5 MATHEMATICAL ITALIC DOTLESS J. They map to the ISOAMSO entities imath and jmath or the [TeX] macros \imath and \jmath which by default are always italic." Perhaps imath should also be changed from U+0131 LATIN SMALL LETTER DOTLESS I to U+1D6A4 MATHEMATICAL ITALIC SMALL DOTLESS I?

Received on Tuesday, 29 January 2008 03:06:00 UTC