Math and MATHML problem

[Wolfgang Zillig <wolfgang.zillig@student.kuleuven.be>]

Hello,

I'm trying to typset some math.

when I use \startbuffer ...here mathml ...\stopbuffer and a following
\processXMLbuffer I get a nice centered formula. When I save that code
to a file  myeq1.xml and try to include it with
\processXMLfile{myeq1.xml}I compillation stops at that point.
\processXMLfilegrouped{myeq1.xml} produces a formula again but 2
additional symbold appear at the beginning of the formula.

Questions:

- What is my fault?

- Whow can I set the alignment of formulas (ie leftaligned)?

Thanks for any help


\usemodule[mathml]
\defineXMLentity [PartialD] {\getXMLentity{differentiald}}
\starttext


\startbuffer
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
  <mrow>
    <mi>q</mi>
    <mo>=</mo>
    <mfrac>
      <mrow>
        <mo>&PartialD;</mo>
        <mi>p</mi>
      </mrow>
      <mrow>
        <mo>&PartialD;</mo>
        <mi>x</mi>
      </mrow>
    </mfrac>
    <mo>=</mo>
    <mo>&PartialD;</mo>
    <mfenced>
      <mrow>
        <mi>&phi;</mi>
      </mrow>
    </mfenced>
    <msub>
      <mi>p</mi>
      <mrow>
        <mi>v</mi>
        <mi>s</mi>
        <mi>a</mi>
        <mi>t</mi>
      </mrow>
    </msub>
    <mfenced>
      <mrow>
        <mi>&theta;</mi>
      </mrow>
    </mfenced>
    <mfrac>
      <mrow>
        <mo>&PartialD;</mo>
        <mi>&phi;</mi>
      </mrow>
      <mrow>
        <mo>&PartialD;</mo>
        <mi>x</mi>
      </mrow>
    </mfrac>
  </mrow>
</math>


\stopbuffer


\processXMLbuffer

\stoptext