| SAXONICA | 
The xsl:choose element is used to choose one of a number of alternative outputs. The element
            typically contains a number of xsl:when elements, each with a separate test condition. The first
            xsl:when element whose condition matches the current element in the source document is expanded, the others
            are ignored. If none of the conditions is satisfied, the xsl:otherwise child element, if any, is
            expanded.
         
The test condition in the xsl:when element is a boolean expression.
            The full syntax of expressions is outlined in XPath Expression Syntax.
         
Example:
<xsl:choose>
    <xsl:when test="@cat='F'">Fiction</xsl:when>
    <xsl:when test="@cat='C'">Crime</xsl:when>
    <xsl:when test="@cat='R'">Reference</xsl:when>
    <xsl:otherwise>General</xsl:otherwise>
</xsl:choose>