As far as I see, there is no way to have both ' (') and " (")
in one XPath literal.

Example:

But as far as I see, there is no way in XPath 1.0 to write a
predicate, which selects such values, because it is not possible to
write an XPath literal which includes both of the possible delimiter
characters of an XPath literal. (A similar example could be easily
constructed for text content of an element.)

To all of my knowledge, the XPath 1.0 syntax has no escaping mechanism
for literal delimiters at all.

Do I miss something?

T:\ftemp>type rolf.xml
<doc>
  <e att="foo">foo</e>
  <e att="a&apos;&quot;b">bar</e>
  <e att="grill">grill</e>
</doc>

T:\ftemp>type rolf.xsl
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:template match="doc">
    <xsl:for-each select="e[@att=concat(&quot;a'&quot;,'&quot;b')]">
      <xsl:value-of select="."/>
    </xsl:for-each>
  </xsl:template>

T:\ftemp>xslt rolf.xml rolf.xsl con
<?xml version="1.0" encoding="utf-8"?>bar
T:\ftemp>

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