title: XML/XSL: Sum in foreach loop with conditional (special case)
body: <p>I have the following XML:</p>
  
  <pre><code>    &lt;root&gt;
   &lt;groups&gt;
    &lt;group id="101"&gt;
     &lt;number&gt;10&lt;/number&gt;
     &lt;children&gt;
      &lt;leader id = "A" /&gt;
      &lt;members&gt;
       &lt;member id="1"&gt;
       &lt;member id="2"&gt;
       &lt;member id="3"&gt;
      &lt;/members&gt;
     &lt;/children&gt;
    &lt;/group&gt;
    &lt;group id="102"&gt;
     &lt;number&gt;20&lt;/number&gt;
     &lt;children&gt;
      &lt;leader id = "A" /&gt;
      &lt;members&gt;
       &lt;member id="4"&gt;
       &lt;member id="5"&gt;
       &lt;member id="3"&gt;
      &lt;/members&gt;
     &lt;/children&gt;
    &lt;/group&gt;
    &lt;group id="103"&gt;
     &lt;number&gt;30&lt;/number&gt;
     &lt;children&gt;
     &lt;leader id = "A" /&gt;
      &lt;members&gt;
       &lt;member id="1"&gt;
       &lt;member id="4"&gt;
       &lt;member id="3"&gt;
      &lt;/members&gt;
     &lt;/children&gt;
    &lt;/group&gt;
   &lt;/groups&gt;
  
  &lt;/root&gt;
  </code></pre>
  
  <p>How can I sum the  property of all the member whom id = 1 using XSL?</p>
  
  <p>Thanks</p>