--- a/rect.xsl	Wed Apr 12 17:43:54 2017 +0100
+++ b/rect.xsl	Wed Apr 12 21:35:04 2017 +0100
@@ -3,36 +3,14 @@
 <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="3.0" xmlns:s="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:e="http://markup.co.uk/excel" exclude-result-prefixes="xs s xpf" xmlns="http://markup.co.uk/excel" xmlns:xpf="http://www.w3.org/2005/xpath-functions">
  <xsl:strip-space elements="s:sheetData"/>
  
+ <xsl:include href="a2n.xsl"/>
+ <xsl:include href="n2a.xsl"/>
+ 
  <xsl:variable name="refs" select="collection()[2]/*"/>
  
  <xsl:key name="ref" match="e:i" use="@r"/>
- 
- <xsl:function name="e:a2n" as="xs:integer">
-  <!-- Convert an alphabetic excel column 'index' into a number,
-       a sort of base 26 + 1, since 'A' is 1 and 'AA' is 27 -->
-  <xsl:param name="aa" as="xs:string"/>
-  <xsl:value-of select="let $l := string-length($aa),
-                        $lv := string-to-codepoints(substring($aa,$l))-$codeBase
-                        return if ($l=1) then $lv
-                               else $lv+(26*e:a2n(substring($aa,1,$l - 1)))"/>
- </xsl:function>
- 
- <xsl:function name="e:n2aa" as="xs:integer*">
-  <!-- Does the real work for e:n2a -->
-  <xsl:param name="n" as="xs:integer"/>
-  <xsl:sequence select="let $least := $codeBase+(($n - 1) mod 26)+1
-                         return if ($n &lt; 27) then $least
-                          else (e:n2aa($n idiv 26),$least)"/>
- </xsl:function>
-
- <xsl:function name="e:n2a" as="xs:string">
-  <!-- Invert the a2n computation -->
-  <xsl:param name="n" as="xs:integer"/>
-  <xsl:value-of select="codepoints-to-string(e:n2aa($n))"/>
- </xsl:function>
 
  <xsl:variable name="dim" select="//s:dimension/@ref"/>
- <xsl:variable name="codeBase" select="string-to-codepoints('A')-1"/>
  
  <xsl:template match="/">
   <xsl:apply-templates select="//s:sheetData"/>