One set of examples of the use of these solidus variations occurs in the mathematics linear format described in Unicode Technical Note #28 (http://www.unicode.org/notes/tn28/UTN28-PlainTextMath-v3.pdf). The ASCII solidus (U+002F) described in Section 2.1 is used to represent normal stacked fractions. So a/b automatically builds up to a "over" b separated by a horizontal fraction bar. The fraction slash (U+2044) is used to input skewed fractions as described later in Section 2.1 along with the division slash (U+2215), which is used to enter large linear fractions. In this approach, the full-width solidus (U+FF0F) is treated as an alias for the ASCII solidus to expedite equation entry with East-Asian IMEs.
U+2215 is a mathematical operator, but the other three appear outside "math zones" in ordinary text. U+FF0F is used in contexts where other full-width Latin letters are present, e.g., in vertical East-Asian layouts. The fraction slash is used to display arbitrary skewed fractions such as ½ when they aren't encoded in Unicode. This is a mathematical context, albeit a simple one. The ASCII solidus is used in various nonmathematical contexts (dates, alternatives) and reminds one of the ASCII hyphen-minus (U+002D) which also has multiple uses. Unicode has other "slashes" such as the U+27CB RISING DIAGONAL. I have a UTC action item to update Unicode Technical Report #25 with some discussion about U+27CB, so I'll generalize Section 2.15 "Fraction Slash" of that report to compare the usages of the various solidi. Murray -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Hans Aberg Sent: Friday, October 07, 2011 7:08 AM To: Unicode Mailing List Subject: Solidus variations There are several solidus (slash) variations. What is the intent of those, in as much there been expressed, in a mathematical context? For example, is U+2044 intended for rational numbers, and U+2215 a long variation of U+002F, which can be used to disambiguate a/b/c/d as in a/b∕c/d = (a/b)/(c/d)? And is U+FF0F intended for non-math use? Hans / U+002F SOLIDUS ⁄ U+2044 FRACTION SLASH ∕ U+2215 DIVISION SLASH ／ U+FF0F FULLWIDTH SOLIDUS
