Add <dc:variable name="variable" expr="xpath"/> construct to datacage language. Each time during traversal of the template this element is found a variable called 'variable' is set to the result of the the evaluation of the XPpath 'xpath'. Example: <dc:variable name="x" expr="$x + 1"/> <!-- Assign x+1 to x -->

<?xml version="1.0" encoding="UTF-8" ?>
<rest-server>
    <!--  The port which the ArtifactDatabase (ArtifactServer) will bind to. -->
    <port>8999</port>
    <listen>localhost</listen>
</rest-server>