Generating XML for a given XSLT

I have an XSLT file and I need to generate the corresponding XML file. I do not know exactly how the XML file is supposed to look like however based on the XSLT, we can guess how it should be.

I need help to understand XSLT properly because I am new to it.

How would the XML file for the below XSLT look like?

<xsl:stylesheet version="1.0" exclude-result-prefixes="xsl math exsl">
<xsl:template match="/library">
<all>
<xsl:if test="count(//cupboards) > 100">
<xsl:message terminate="yes">Too many cupboards</xsl:message>
</xsl:if>
<xsl:variable name="val_a">
<value>
<xsl:value-of select="round(math:random() * 10000)"/>
</value>
<value>
<xsl:value-of select="round(math:random() * 10000)"/>
</value>
</value>
</xsl:variable>

<xsl:call-template name="check-library">
<xsl:with-param name="val_a" select="exsl:node-set($val_a)//value"/>
<xsl:with-param name="val_b" select="1"/>
<xsl:with-param name="val_c" select="val_c[position() = 1]/cupboards"/>
<xsl:with-param name="val_d" select="state/val_d"/>
</xsl:call-template>
</all>
</xsl:template>

<xsl:template name="check-library">
<xsl:param name="val_a"/>
<xsl:param name="val_b"/>
<xsl:param name="val_c"/>
<xsl:param name="val_d"/>
<xsl:if test="$val_b > 20000">
<xsl:message terminate="yes">Check 1</xsl:message>
</xsl:if>

<xsl:if test="count($val_d) > 200">
<xsl:message terminate="yes">
Check 2
</xsl:message>
</xsl:if>

<xsl:if test="count($val_c) > 0">
<xsl:variable name="c" select="$val_c[1]"/>
<xsl:variable name="r" select="$val_c[position()>1]"/>
<xsl:choose>
<xsl:when test="count($c/something) = 1">
<xsl:message>
<val_a>
<xsl:copy-of select="$val_a"/>
</val_a>
</xsl:message>

<xsl:message>
<val_d>
<xsl:copy-of select="$val_d"/>
</val_d>
</xsl:message>

<xsl:call-template name="check-library">
<xsl:with-param name="val_a" select="$val_a"/>
<xsl:with-param name="val_b" select="$val_b + 1"/>
<xsl:with-param name="val_c" select="$r"/>
<xsl:with-param name="val_d" select="$val_d"/>
</xsl:call-template>

<xsl:when test="count($c/something2) = 1">
<xsl:variable name="val_e">
<value>
<xsl:value-of select="$c/something2 + 0"/>
</value><xsl:copy-of select="$val_d"/>
</xsl:variable>

<xsl:call-template name="check-library">
<xsl:with-param name="val_a" select="$val_a"/>
<xsl:with-param name="val_b" select="$val_b + 1"/>
<xsl:with-param name="val_c" select="$r"/>
<xsl:with-param name="val_d" select="exsl:node-set($val_e)//value"/>
</xsl:call-template>
</xsl:when>

I tried to make an XML as shown below:

<?xml version="1.0" encoding="UTF-8"?>
<library>
<val_c>
<cupboards>
<something>
</something>
</cupboards>
</val_c>
</library>
<state>
<val_d>
something
</val_d>
<state>

However, it is not the correct XML.

If I put more than 100 cupboard child nodes for library tree node, I get the message: "Too many cupboards". So, that part is correct.

But I don't understand how the checks are being performed in the check-library template.

Could someone help me understand this XSLT and also show how the corresponding XML should look like?

Then, I can write code to automatically generate the XML for a given XSLT of this form.

Thanks.