Re: minor grouping issue

It's probably simplest to put the xsl:number within an xsl:choose to
distinguish the two cases.

  <xsl:function name="db:number-footnote" as="xs:string">
    <xsl:param name="footnote" as="element(db:footnote)"/>
    <xsl:choose>
      <xsl:when test="$chapters/db:chapter">
        <xsl:number level="any" count="$footnote" from="db:chapter"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:number level="any" count="$footnote"/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:function>

F XPath syntax error at char 0 in {$footnote}:
    Unexpected token in pattern, found "$"