my $parser = XML::LibXML->new() or die $!;
 my $doc1 = $parser->parse_file($filename1);
 my $xc1 = XML::LibXML::XPathContext->new($doc1->documentElement() );
 $xc1->registerNs(x => 'http://checklists.nist.gov/xccdf/1.1');
 $xc1->registerNs(dc => 'http://purl.org/dc/elements/1.1');


 for $Check ( $xc1->findnodes('//x:Rule') ) { 

     my $doc2 = $parser->parse_string($Check);
     my $xc2 = XML::LibXML::XPathContext->new($doc2->documentElement() );
     $xc2->registerNs(x => 'http://checklists.nist.gov/xccdf/1.1');


     foreach $Check_Content ( $xc2->findvalue('check-content') ) { 

          push (@Check_Content1, $Check_Content);

          }

     @Check_Content1 = ();           

     $result_string = $Check_Content1[0] . $Check_Content1[1];
     push (@Check_Content, $result_string);
     }
 }