Re: Docbook: Customising DTD to allow xinclude in place of mml:math within equations.

Dear all

I have been searching for the answer to a problem in the mailing list
archives, but haven't been able to find it. I am hoping you might be
able to help me out.

I have previously followed the instructions here
(http://www.sagehill.net/docbookxsl/MathML.html) that show how to
customise the DTD to allow MathML to be included within equation,
inlineequation and informalequation elements.

I have just decided to follow the instructions here
(http://www.sagehill.net/docbookxsl/ValidXinclude.html), which explain
how to customise the DocBook DTD to allow xincludes in place of
various elements. I would like to extend this to allow xincludes in
place of the mml:math element within equation, inlineequation and
informalequation elements, so that something like

<equation>
  <xi:include href="math.xml" xmlns:xi="http://www.w3.org/2001/XInclude" />
</equation>

will validate too (using xmllint).

I guess I need to extend the examples given in the references above by
adding lines similar to

<!ENTITY % equation.mml:math.content "| xi:include">
<!ENTITY % inlineequation.mml:math.content "| xi:include">
<!ENTITY % informalequation.mml:math.content "| xi:include">

to my DTD but I don't know the correct syntax.

Can someone (Bob) help me out here please?

Thank you,

Paul