DoubleLongLeftArrow character entity

David Carlisle <davidc@nag.co.uk> writes to www-math@w3.org
Re: "Typo in character entities tables?":

[snip]
> > introduced in MathML 1.0 and excluded in 2.0?
> 
> more or less. There were more of these originally. They relate to 
> characters in MathML 1 and/or the STIX submission that didn't make it
> into the proposals for Unicode 3.1 or 3.2.
[snip]
> The DTD currently defines &DoubleLongLeftArrow; as &#x21D0; (without the
> trailing x). Which means that DoubleLongLeftArrow is the same as 
> DoubleLeftArrow. So now that the Unicode proposals have stabalised and
> (unfortunately) the long arrows are definitely not in,
[snip]

Ummm... gee, back in pre-history I seem to remember assembling
&DoubleLongLeftArrow; and its mirror twin from pieces in a fix-width
early printer font.

Long arrows arise in academic journals in many disciplines.

So why were they left out of unicode?

Anyway, the circumstance points out the need for standard network ways
of serving, fetching, caching, and referencing new character glyphs,
because the collection of them is, in fact, a growing thing.  (The
newest one that everyone on this planet knows about is probably the
euro symbol.)

It's not just about MathML.

Have such needs been considered?

I hope this does not mean that one will need to resort to SVG images
for new glyphs.

                                    -- Bill

Received on Thursday, 11 January 2001 11:33:38 UTC