title: LINQ query where complete group meets a condition
body: <p>I have stored a lot of text lines like this:</p>
  
  <pre><code>1|1000|1|0|Text Message|||
  1|1000|1|1|Text Message|||
  1|1000|2|0|Text Message|||
  1|1000|2|1|Text Message|||
  1|1000|3|0|Text Message|||
  1|1001|1|0|Text Message|||
  </code></pre>
  
  <p>in a Collection: <code>List&lt;ObjRow&gt; listRows</code></p>
  
  <p>and this is the corresponding Class:</p>
  
  <pre><code>public class ObjRow
  {
      private string n_Par { get; set; }
      private string n_Rad { get; set; }
      private string n_Lang { get; set; }
      private string n_Line_Mex { get; set; }
      private string text_Mex { get; set; } 
      private int n_Row { get; set; }
  }
  </code></pre>
  
  <p>I would like to find which groups of lines (grouped by property <code>n_Rad</code>, 2° PIPE value) which have not the value <code>n_Lang == 3</code> (3° PIPE value).  </p>
  
  <p>How to do this with LINQ?</p>