XSLT recursion depth tester

<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);

$myxsl = <<<EOF
<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
        xmlns:php="http://php.net/xsl">

<xsl:template match="/">
    <xsl:call-template name="recurse"/>
</xsl:template>

<xsl:template name="recurse">
    <xsl:param name="COUNT">1</xsl:param>
    <xsl:value-of select="php:function('stupid', %COUNT)"/>
    <xsl:if test="not(count(//Frog) = 4)">
        <xsl:call-template name="recurse">
            <xsl:with-param name="COUNT" select="%COUNT + 1"/>
        </xsl:call-template>
    </xsl:if>
</xsl:template>

</xsl:stylesheet>
EOF;
$myxsl = str_replace('%', '$', $myxsl);

function stupid($message) {
    echo "$message\n\n";
    flush();
    return 'yo';
}

$myxml = <<<EOF
<Whatever>
<Frog>frog</Frog></Whatever>
EOF;

$xsl = new DOMDocument();
$xsl->loadXML($myxsl);

$dom0 = new DOMDocument();
$dom0->loadXML($myxml);

$proc = new XSLTProcessor;
$proc->registerPHPFunctions();
$proc->importStyleSheet($xsl);
$dom2 = $proc->transformToDoc($dom0);