I seem to have a problem using the preceding:: on substrings of the
value.  I'll try to explain with an example:

Let's say I had a XML that look like:

<Root>
    <Row>
        <Cell Name="Street" Value="2nd Street" />
    </Row>
     <Row>
        <Cell Name="Street" Value="Meadow Lane" />
    </Row>
    <Row>
        <Cell Name="Street" Value="2nd Street" />
    </Row>
   <Row>
        <Cell Name="Street" Value="2nd Street" />
    </Row>
    <Row>
        <Cell Name="Street" Value="Meadow Lane" />
    </Row>

</Root>

Let's say I want to find the distinct streets.  This is straight
forward and may look something like:


<xsl:template match="Root">
	<xsl:element name="root">


		<xsl:for-each select="./Row[Cell[@Name = 'Street' and not(@Value =
preceding::Cell[@Name= 'Street']/@Value) ]]">

			<xsl:variable name="UniqueStreet" select="./Cell[@Name='Street']/
@Value"/>

			<xsl:element name="street">
				<xsl:attribute name="name">
					<xsl:value-of select="$UniqueStreet"/>
				</xsl:attribute>

				<!-- This is where I would reiterate through the list to get the
list of residents
						that live on that block -->
			</xsl:element>
		</xsl:for-each>
	</xsl:element>
</xsl:template>

This returns what I expect:

<root>
  <street name="2nd Street"/>
  <street name="Meadow Lane"/>
</root>

But let's say the address contained street numbers, and I needed to
strip out the street numbers when trying to look for unique street
names.


<Root>
    <Row>
        <Cell Name="Address" Value="1345 2nd Street" />
    </Row>
    <Row>
        <Cell Name="Address" Value="332 Meadow Lane" />
    </Row>
	<Row>
        <Cell Name="Address" Value="333 2nd Street" />
    </Row>
	<Row>
        <Cell Name="Address" Value="8534 2nd Street" />
    </Row>
	   <Row>
        <Cell Name="Address" Value="556 Meadow Lane" />
    </Row>

</Root>

	<xsl:template match="Root">
		<xsl:element name="root">


				<xsl:for-each select="./Row[Cell[@Name = 'Address' and
not(substring-after(@Value, ' ') = substring-
after(preceding::Cell[@Name= 'Address']/@Value, ' ')) ]]">

					<xsl:variable name="UniqueStreet" select="substring-after(./
Cell[@Name='Address']/@Value, ' ')"/>

					<xsl:element name="street">
						<xsl:attribute name="name"><xsl:value-of select="$UniqueStreet"/
></xsl:attribute>

						<!-- This is where I would reiterate through the list to get the
list of residents
							that live on that block -->
					</xsl:element>
				</xsl:for-each>
		</xsl:element>
	</xsl:template>

This yields the output:

<root>
  <street name="2nd Street"/>
  <street name="Meadow Lane"/>
  <street name="Meadow Lane"/>
</root>

Can someone explain why that is happening and how I can fix it?