W3C home > Mailing lists > Public > public-html@w3.org > March 2008

Re: Exploring new vocabularies for HTML

From: David Carlisle <davidc@nag.co.uk>
Date: Sun, 30 Mar 2008 00:52:46 GMT
Message-Id: <200803300052.m2U0qkbM025716@edinburgh.nag.co.uk>
To: ian@hixie.ch
Cc: public-html@w3.org, www-math@w3.org

> Sure, but if we have both, and someone then hand-edits one of them and 
> leaves the other alone, then they become out of sync and interoperability 
> becomes a nightmare. We actively want to avoid the Web having multiple 
> redundant representations of content, it's an anti-pattern that has caused 
> any number of issues in the past.

It's not that that is not a valid concern. ideally  you want the rule
that if any branch of a semantics element is edited, all other branches
are regenerated (or discarded if that isn't possible) but to simply say
that sematics shouldn't be supported would be a very backward step.

The most important usage is anotating presentation mathml (For display)
with Content MathmL (For mathematical meaning). It's probably not going
to be feasible to mandate that all systems support content mathml
rendering, which as you say involves a lot of elements and a lot of
math-specific processing. Even when content rendering is available,
authors may want, for localisation or orther reasons, to supply a
preferred presentation mathml rendering.

So the preferred solution is to use presentation mathml on the web page
and annotate it with the content mathml. To just serve the presentation
form over the web reduces the semantic content of the document, harms
accessibility and harms re-use of the expressions. Of course simple
cases you can re-process the presentation mathml and infer the
semantics, but in many cases you can not, which is the whole point of
content mathml.

> We actively want to avoid the Web having multiple 
> redundant representations of content

annotating a presentation format with its meaning is not redundancy.

> (Boy there are a lot of MathML elements, even in Presentation MathML.)

not really, presentational mathematics is a bunch of special layout
forms, and compared to say the markup html uses for tables, the level of
element use per layout form is similar. (except as previously commented
tokens such as numbers and identifiers are marked up individually).

> What I'm basically looking for is something that just lists the elements 
> and then for each one lists what elements are allowed as
> children. e.g.:

There are probably some relax ng pretty printers, or there's always the
toc of chapte 3 of the spec. But if you want some other format let us
know and we can probably generate something.


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Received on Sunday, 30 March 2008 00:53:22 UTC

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