<?xml version="1.0" encoding="UTF-8"?>
<xsl:transform version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
>

<!-- merge sibling elements, maybe separated with blankspace nodes -->

<xsl:template match="*">
  <xsl:copy><xsl:copy-of select="@*"/><xsl:apply-templates/></xsl:copy>
</xsl:template>

<xsl:template match="text()[not( normalize-space() )]" mode="greek"/>

<xsl:template match="text()[not( normalize-space() )][ following-sibling::node()[self::spoj] ]" mode="greek">
  <xsl:text> </xsl:text>
</xsl:template>

<xsl:template match="spoj" mode="greek">
  <xsl:apply-templates/>
</xsl:template>

<xsl:template match="defpozn">
  <comment><xsl:copy-of select="@*"/>
    <xsl:copy-of select="node()[1][self::text()]"/>
    <xsl:if test="spoj">
    <expression>
      <xsl:apply-templates select=" spoj[1] | spoj[1]/following-sibling::node()" mode="greek"/>
    </expression>
    </xsl:if>
  </comment>
</xsl:template>

<xsl:template match="defpozn[ *[ not(self::spoj)] ] | defpozn[ spoj[1]/following-sibling::text()[ normalize-space() ] ] ">
  <xsl:message terminate="yes">
    <xsl:text>Not supported:</xsl:text>
    <xsl:copy-of select="."/>
  </xsl:message>
</xsl:template>


<xsl:output
  encoding="UTF-8"
  indent="yes"
  method="xml"
/>

</xsl:transform>