anchor.diff:              "PARAM"
           ]
           |> List.exists (fun x -> x.ToLower() = name.ToLower())
  -        
  -    
  +
  +
       /// Writes HTML nodes to an XmlWriter.
       [<Sealed>]
       type Writer (writer: HtmlTextWriter) =
  
positive.code:                 writer.WriteAttribute(a.Name, a.Value)
              writer.Write(HtmlTextWriter.SelfClosingTagEnd)
  
          // Renders tag with content. 
          // E.g. <div class="c">...</div>
          member private this.RenderElementWithContent    name
                                              (attrs: list<Attribute<'T>>) 
                                              (contents : list<Element<'T>>) =
              writer.WriteBeginTag(name)
              for a in attrs do
                  writer.WriteAttribute(a.Name, a.Value)
              writer.Write(HtmlTextWriter.TagRightChar)
          
              // Render contents
              for content in contents do
                  this.Write content
  
negative.code:             elements
              |> Seq.choose (fun x ->
                  match x.Node with
                  | AttributeNode x -> Some x
                  | _ -> None)
              |> Seq.toList
  
          let selCnt (x: INode<_>) =
              match x.Node with
              | ContentNode x -> Some x
              | _ -> None
  
          let contents =
              elements
              |> Seq.choose selCnt
              |> Seq.toList
          {
              Name = name
              Attributes = attrs
              Contents = contents
              Annotation = None
          }
          |> TagContent
  
  