HtmlAgilityPack SelectNodes expression to ignore an element with a certain attribute

Question 1

Given an Html document with a structure similar to:

<html>
<head><title>HtmlDocument</title>
</head>
<body>
<div>
<span>Hello Span World</span>
<script>
Script Text
</script>
</div>
<ul class='relativeNav'>
<li>Hello </li>
<li>Li</li>
<li>World</li>
</ul>
</body>
</html>

The following XPath expression will select all nodes which are not script elements excluding all children of UL elements with class 'relativeNav':

var nodes = htmlDoc.DocumentNode.SelectNodes("//body//*[not(parent::ul[@class='relativeNav']) and not(self::script)]/text()");

Update: forgot to mention that if you need to exclude any children of ul[class='relativeNav'] irrespective of their depth you should use:

"//body//*[not(ancestor::ul[@class='relativeNav']) and not(self::script)]/text()"

If you wanted to exclude the ul element as well (somewhat irrelevant in the example above since the element does not contain text) you should specify:

"//body//*[not(ancestor-or-self::ul[@class='relativeNav']) and not(self::script)]"

Question 2

I hope this is what you need:

HtmlDocument doc = new HtmlDocument();
var nodesToExclude1 = doc.DocumentNode.SelectNodes("//ul[@class='relativeNav']");
var nodesToExclude2 = doc.DocumentNode.SelectNodes("//body//script");
var requiredNodes = doc.DocumentNode.SelectNodes("//")
                       .Where(node => !nodesToExclude1.Contains(node) &&
                                      !nodesToExclude2.Contains(node));

foreach (HtmlNode node in requiredNodes)
{
    Console.WriteLine("Node: " + node);
    singleString += node.InnerText.Trim() + "\n";
}