$re = '/(is_granted\()\[(\W.+?)\]/m';
$str = '"expr(not is_granted([\'SITE_PERMISSION_VIEW_AUDIT_ANSWER_OPTIONS\']) and not is_granted([\'SITE_PERMISSION_CREATE_AUDITS\']) and not is_granted([\'SITE_PERMISSION_CREATE_AUDIT_TEMPLATES\']))",';
$subst = "$1$2";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php