Creating semantic tables with rowspan via xslt

I have following xml document:

...

<x>
<symptom><descr></descr></symptom>
<cause></cause>
<solution></solution>
<cause></cause>
<solution></solution>
</x>

...

In my document I have several <x>

In each <x> I have only one <symptom> and n <cause> and <solution> whereby the amount of <cause> and <solution> is always the same.

I want to get following autmatically generated structure:

<table>
<tr>
<td rowspan=count(cause)><xsl:value-of select="symptom/descr"></td>
<td><xsl:value-of select="cause"></td>
<td><xsl:value-of select="symptom"></td>
<tr>
<tr>
<td><xsl:value-of select="cause"></td>
<td><xsl:value-of select="symptom"></td>
<tr>
...
</table>

I tried following code, which I know is totally wrong. But I'm stuck since several hours and couldn't find any good solution on the internet.

    <xsl:for-each select="cause">
             <tr>
               <td rowspan="count(.)">
                 <xsl:value-of select="../descr[1]"/>
               </td>
               <td>
                 <xsl:value-of select="."/>
               </td>
               <xsl:for-each select="../solution">
                <td>
                 <xsl:value-of select="."/>
               </td>
</xsl:for-each>
 </tr>
             </xsl:for-each>
      </table>