Checking multiple occurrences and manipulating them using XSLT - xslt

Question

I have a requirement in which I need to check all four values of both occurrences in one condition and it is not given that hey1 and hello1 will come in one occurrence and hey2 and hello2 in the other.
I mean it is not guaranteed that hey1 or hey2 come in as first or second; the same applies for hello1 and hello2.
I am using the below code which gives me the output <output>ININ</output>, but I need it as <output>IN</output>.
I am trying this POC and I have a sample XML below:
<q>
<a>
<b>hey1</b>
<c>hello1</c>
</a>
<a>
<b>hey2</b>
<c>hello2</c>
</a>
</q>
Kindly provide me a solution which checks all four conditions and in which one if/when condition used for each <a> will occur twice or multiple times.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format">
<xsl:output encoding="UTF-8" version="1.0" method="xml" indent="yes"/>
<xsl:template match="/">
<xsl:variable name="a" select="/q/a"/>
<output>
<xsl:for-each select="$a">
<xsl:if test="$a/b='hey1' and $a/c= 'hello1' and $a/b='hey2' and $a/c= 'hello2'">
<xsl:value-of select="'IN'"/>
</xsl:if>
</xsl:for-each>
</output>
</xsl:template>
</xsl:stylesheet>
I hope that I my question is clear enough to answer it.
Thank you for any advice.

Answer 1

Try:
<xsl:template match="q">
<xsl:if test="a[b='hey1' and c='hello1'] and a[b='hey2' and c='hello2'] ">
<xsl:text>IN</xsl:text>
</xsl:if>
</xsl:template>
This will return "IN" for both:
<q>
<a>
<b>hey1</b>
<c>hello1</c>
</a>
<a>
<b>hey2</b>
<c>hello2</c>
</a>
</q>
and:
<q>
<a>
<b>hey2</b>
<c>hello2</c>
</a>
<a>
<b>hey1</b>
<c>hello1</c>
</a>
</q>
but not for:
<q>
<a>
<b>hey1</b>
<c>hello2</c>
</a>
<a>
<b>hey2</b>
<c>hello1</c>
</a>
</q>