title: Not equal/not contains operation in lambda expressions
body: <p>My query is some thing like:</p>
  <pre><code>var subQuery = contacts_requests.Where(i =&gt; i.requests_usr_id &gt;= 1).Select          
             (i =&gt; i.Usr_contacts_requests_from_usr_id ).ToArray();
  var query = biographic_details.Join(profiles_companies, i =&gt; i.usr_id, j =&gt; j.company_usr_id,
             (i,j)=&gt;new{
                        Usr_bio_usr_id }).where(p=&gt;subQuery.Contains(i.company_usr_id)).ToArray();
  </code></pre>
  <p>I want notcontains operation in place of contains, how can I implement that?</p>