<xsl:choose>

• xsl:choose is necessary when you need an "otherwise"
• "otherwise" is like "else"
• Only one option is chosen, or else "otherwise"

  <xsl:choose>
          <xsl:when test="ancestor(unorderedlist)">
                  *
          </xsl:when>
          <xsl:when test="ancestor(unorderedlist/unorderedlist)">
                  +
          </xsl:when>
          <xsl:otherwise>
                  -
          </xsl:otherwise>
  </xsl:choose>