+<!-- S and O -->
+<xsl:template match="APPLY[*[position()=1 and name()='MUTCONSTRUCT' and @uri='cic:/Coq/Init/Datatypes/nat.ind' and @noConstr='2'] and count(*)=2]" mode="pure">
+ <xsl:apply-templates select="*[2]" mode="succ">
+ <xsl:with-param name="n" select="1"/>
+ <xsl:with-param name="iden" select="@id"/>
+ </xsl:apply-templates>
+</xsl:template>
+
+<xsl:template match="*" mode="succ">
+ <xsl:param name="n" select="0"/>
+ <xsl:param name="iden" select="''"/>
+ <xsl:choose>
+ <xsl:when test="name()='APPLY' and *[position()=1 and name()='MUTCONSTRUCT'
+and @uri='cic:/Coq/Init/Datatypes/nat.ind' and @noConstr='2']">
+ <xsl:apply-templates select="*[2]" mode="succ">
+ <xsl:with-param name="n" select="$n +1"/>
+ <xsl:with-param name="iden" select="$iden"/>
+ </xsl:apply-templates>
+ </xsl:when>
+ <xsl:when test="name()='MUTCONSTRUCT' and @uri='cic:/Coq/Init/Datatypes/nat.ind' and @noConstr='1'">
+ <m:cn helm:xref="{$iden}"><xsl:value-of select="$n"/></m:cn>
+ </xsl:when>
+ <xsl:otherwise>
+ <m:apply helm:xref="{$iden}">
+ <m:plus/>
+ <m:cn><xsl:value-of select="$n"/></m:cn>
+ <xsl:apply-templates select="." mode="pure"/>
+ </m:apply>
+ </xsl:otherwise>
+ </xsl:choose>
+</xsl:template>
+
+