Setting doctype in output files

Hello,

I am using an XSL stylesheet to extract SVG and MathML resources from a docbook
file. Extraction works fine, except the fact that the file created through xalan
redirection have the same doctype as the one specified in the xsl:output of the
stylesheet. Because i generate .svg (1.0) and .mml (2.0), i would like these
file to have the appropriate doctypes.

I tried not to specify a doctype in the xsl:output, and "print" each doctype in
the relevant templates, but i get a message like "no doctype allowed in
content". And if i try to change the < > and the doctypes to &lt; and &gt; to
prevent their detection, these entities are not converted to < and > when output.

I haven't found related information in the xalan documentation, or javadoc. Is
it possible, or should i do it another way ?

Thanks in advance,
Nicolas