XSLT separator for sequence not separating

Question

I'm using XSLT 2.0 to create a spreadsheet and am having trouble getting a sequence to separate properly. I'm trying to match the subfields that are Slovak (code=2 value is SNKPH) and output the text value of it's sibling subfield (code=a).

My ideal output would be "fotografie; ferotypia". What I'm actually getting is "fotografieferotypia". I'm not sure what I'm doing wrong.

Sample data:

<marc:collection>
   <marc:record>    
      <marc:datafield tag="655" ind1=" " ind2="7">
         <marc:subfield code="a">fotografie</marc:subfield>
         <marc:subfield code="2">SNKPH</marc:subfield>
      </marc:datafield>
      <marc:datafield tag="655" ind1=" " ind2="7">
         <marc:subfield code="a">ferotypia</marc:subfield>
         <marc:subfield code="2">SNKPH</marc:subfield>
      </marc:datafield>
      <marc:datafield tag="655" ind1=" " ind2="7">
         <marc:subfield code="a">Photographs</marc:subfield>
         <marc:subfield code="2">SNKPHeng</marc:subfield>
      </marc:datafield>
      <marc:datafield tag="655" ind1=" " ind2="7">
         <marc:subfield code="a">Ferrotype</marc:subfield>
         <marc:subfield code="2">SNKPHeng</marc:subfield>
      </marc:datafield>
   </marc:record>
</marc:collection>

Sample code

<xsl:template match="/">header
   <xsl:apply-templates/>
</xsl:template>
<xsl:template match="marc:record">
   <xsl:variablename="slk_655">
      <xsl:for-each select="marc:datafield[@tag='655']">
        <xsl:choose>
          <xsl:when test="./marc:subfield[@code='2' and text()='SNKPH']">
            <xsl:value-of select="./marc:subfield[@code='a']"/>
          </xsl:when>
          <xsl:otherwise/>
        </xsl:choose>
      </xsl:for-each>
   </xsl:variable>
   <xsl:value-of select="$slk_655" separator="; "/>
</xsl:template>

Answer 1

Simply use <xsl:value-of select="marc:datafield[@tag = '655' and marc:subfield[@code = '2' and . = 'SNKPH]]/marc:subfield[@code = 'a']" separator="; "/>.