[Om3] A dynamic future?

[c.a.rowley at open.ac.uk]

David

Thanks.  Some more questions.

> any other expressions are not invalid but are currently undefined in
mathml3.

Would that have to be 'any expression'?  Or just anything within a single
element <extension> element?

> This allows arbitrary future extension but gives up on any error
> checking or schema context driven editing help on current documents.

Agreed, unless we also provide a method of specifying these (but I guess
that the XML does not allow modification of the parsing...:-(??)

Would it be useful nevertheless provide simple support for such extensions
so that
future developments could at least be prototyped using existing MML-aware
tools and tested in 'real-life' MML stuff?

>>
But the OM design really is for a fixed stable set of primitives
with exteibility being by the CD mechanism specifically so it doesn't
require XML level schema changes to extend. That's not to say that OM
shouldn't be extended occasionally but that should be rather more rare
than most XML vocabularies.
>>

Yes, I understand that: I guess that I am thinking only about MML3 at
present, and the possibility of easing future alignment with such an
unexpected beast as a 'better OM':-) or other systems developed to express
a larger range of 'mathematical information/knowledge'.

>>
In particular every MathML expression is supposed to have a default
rendering so the more you open up the schema the more you have to
specify (or wave hands to avoid specifying) what some arbitrary
construct is supposed to look like.
>>

Is there not already a 'default' of (almost) just printing out the XML
structure (or just the code)?

And is there not already a mechanism for specifying presentations?  Within
MML itself or externally?

Is not this kind of thing already needed to allow the use of other OM2 CDs?


chris
(just off to find out how to get money out of the UK government, having not
chosen to go into the financial sector about 35 years ago:-)

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