From: Doug Ewell (firstname.lastname@example.org)
Date: Thu Apr 14 2011 - 13:40:14 CDT
Hans Aberg <haberg dash 1 at telia dot com> wrote:
>> After Unicode has finished adding superscript versions of every
>> imaginable math character, including all of the math alphanumerics,
>> it would then have to add second-level, third-level, etc. versions of
>> every character, so that one could enter "a to the b to the c to the
>> (d times square root of 2)" in plain text. And don't forget
>> subscripts of superscripts, and vice versa.
> One way would be to enter a^b^c^(d·√2), only that '^' would be a
> special superscript symbol. If the parser is intelligent enough, it
> can infer that the parenthesizes are not needed in the rendering.
Here you are positing a math-specific "parser" that accepts a plain-text
expression in programming-language syntax, and displays an attractively
styled, human-readable or compiled version of that expression. I assume
such parsers are in common use, and I'm not talking about that. Maybe
my use of "enter" was misleading.
You had written, "Unicode does not have characters for say superscripts
and subscripts, which are essential to math. My guess it would be too
complicated to require it for current text-only renderers, but in the
future that might change." You added examples of different types of
application that care about either the appearance or the semantics of
What I am trying to say is that encoding a comprehensive, or even
minimally usable, set of superscript and subscript varieties of existing
characters would not solve either the direct-layout problem or the
semantic-layout problem, because of nesting and other aspects of math
layout; and that, as Murray illustrated, an attempt to solve these
problems more fully by encoding even more characters would become
exponentially more complex and bulky.
-- Doug Ewell | Thornton, Colorado, USA | RFC 5645, 4645, UTN #14 www.ewellic.org | www.facebook.com/doug.ewell | @DougEwell
This archive was generated by hypermail 2.1.5 : Thu Apr 14 2011 - 13:44:39 CDT