Key Match using accumulators in XSLT3 - xslt-3.0

Question

I am looking to use accumulators in my xslt3 below and process only unmatched keys and ignore others.
I want loop through each All_Time_Offs/Time_Off and if Time_Off_Key is present in the Payroll_Input/Input_Key -> Then do not process. Else process the record
<?xml version="1.0" encoding="UTF-8"?>
<Aggregated_TimeOffs>
<All_Payroll_Inputs>
<Payroll_Input>
<RefID>PAYROLL_INPUT-6-122898</RefID>
<Emp_ID>101058</Emp_ID>
<Earning>101D</Earning>
<Start_Date/>
<Adjustment>0</Adjustment>
<Hours>4</Hours>
<Input_Key>PAYROLL_INPUT-6-122898101D4</Input_Key>
</Payroll_Input>
<Payroll_Input>
<RefID>PAYROLL_INPUT-6-122898</RefID>
<Emp_ID>101058</Emp_ID>
<Earning>101D</Earning>
<Start_Date/>
<Adjustment>0</Adjustment>
<Hours>4</Hours>
<Input_Key>PAYROLL_INPUT-6-122898101D9</Input_Key>
</Payroll_Input>
</All_Payroll_Inputs>
<All_Time_Offs>
<Time_Off>
<RefID/>
<Emp_ID>29519</Emp_ID>
<Earning/>
<Date>2020-09-10</Date>
<Adjustment/>
<Hours>7</Hours>
<Cost_Center/>
<Week>Week_2</Week>
<Time_Off_Key>PAYROLL_INPUT-6-122898101D4</Time_Off_Key>
</Time_Off>
<Time_Off>
<RefID/>
<Emp_ID>68413</Emp_ID>
<Earning/>
<Date>2020-09-09</Date>
<Adjustment/>
<Hours>8</Hours>
<Cost_Center/>
<Week>Week_2</Week>
<Time_Off_Key>INT024_PAYROLL_INPUT_2020-09-098</Time_Off_Key>
</Time_Off>
</All_Time_Offs>
</Aggregated_TimeOffs>
Below is the XSLT I am trying, but not working.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:map="http://www.w3.org/2005/xpath-functions/map"
xmlns:err="http://www.w3.org/2005/xqt-errors"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:ext="urn:SomeExternalSource"
xmlns:xtt="urn:com.workday/xtt"
xmlns:wd="urn:com.workday/bsvc"
xmlns:this="urn:com.workday/this"
exclude-result-prefixes="xs ext map wd xtt this"
version="3.0">
<xsl:output method="xml" indent="yes" omit-xml-declaration="yes"></xsl:output>
<xsl:mode streamable="yes" on-no-match="shallow-skip" use-accumulators="Time_Off_Key Payroll_Input_lookup emp.id"/>
<xsl:accumulator name="Payroll_Input_lookup" as="xs:string" initial-value="''" streamable="yes">
<xsl:accumulator-rule match="Input_Key/text()" select="."/>
</xsl:accumulator>
<xsl:accumulator name="Time_Off_Key" as="map(xs:string,xs:string)" initial-value="map{}" streamable="yes">
<xsl:accumulator-rule match="Time_Off_Key/text()" select="map:put($value, string(.), accumulator-before('Payroll_Input_lookup'))"/>
</xsl:accumulator>
<xsl:accumulator name="emp.id" streamable="yes" as="xs:string" initial-value="''">
<xsl:accumulator-rule match="Emp_ID/text()" select="."/>
</xsl:accumulator>
<xsl:template match="Aggregated_TimeOffs">
<xsl:for-each select="All_Time_Offs/Time_Off/copy-of()">
<xsl:variable name="input_exists">
<xsl:value-of select="accumulator-before('Time_Off_Key')(normalize-space(Time_Off_Key))"/>
</xsl:variable>
<xsl:if test="string-length($input_exists) < 0">
<xsl:copy-of select="."/>
</xsl:if>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>

Answer 1

If you only want to compare the single values Time_Off_Key occured during "earlier" parsing of the Payroll_Input/Input_Key values then a single, xs:string*, i.e. string sequence based accumulator should suffice:
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
version="3.0"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="#all"
expand-text="yes">
<xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>
<xsl:mode streamable="yes" on-no-match="shallow-skip" use-accumulators="Payroll_Input_Input_Keys"/>
<xsl:accumulator name="Payroll_Input_Input_Keys" as="xs:string*" initial-value="()" streamable="yes">
<xsl:accumulator-rule match="Payroll_Input/Input_Key/text()" select="., $value"/>
</xsl:accumulator>
<xsl:template match="Time_Off[copy-of()[not(Time_Off_Key = accumulator-before('Payroll_Input_Input_Keys'))]]">
<xsl:copy-of select="."/>
</xsl:template>
</xsl:stylesheet>
It might not be streamable, however, as the use of copy-of() in the predicate of the pattern breaks the motion-less requirement of streamable patterns: so we need to write
<xsl:template match="Time_Off">
<xsl:copy-of select="copy-of()[not(Time_Off_Key = accumulator-before('Payroll_Input_Input_Keys'))]"/>
</xsl:template>
instead to make that code work with streaming.