[Om] invisible times and invisible plus

[Christoph LANGE]

Dear James,

2009-08-31 17:06 Professor James Davenport <jhd at cs.bath.ac.uk>:
> I suspect we want to be able to write
> <OMATTR>
>   <OMATP>
>     <OMS cd="presentation_hacks" name="use_symbol"/>
>     <OMFOREIGN encoding="MathML-Presentation">
>       <math xmlns="http://www.w3.org/1998/Math/MathML">
>         <mo>&InvisiblePlus;</mo>
>       </math>
>     </OMFOREIGN>
>   </OMPATP>
>   <OMS name="plus" cd="arith1"/>
> </OMATTR>
>
> or some such.

Indeed, good point.  I think that would almost work out of the box with
the existing implementations of renderers.

However, it may easily become more intricate.  Suppose the default way of
rendering division (according to some *.ntn notation dictionary) is a/b
instead of

 a
---
 b

then the approach above would no longer work.  Instead we'd have to attribute
the complete (plus a (divide b c)) expression with, well, maybe some
Presentation MathML fragment with placeholders that would then be replaced by
the renderings of the respective arguments.  Something similar to the patterns
in those pattern-matching-based notations.

Cheers,

Christoph

-- 
Christoph Lange, Jacobs Univ. Bremen, http://kwarc.info/clange, Skype duke4701