@ID = qw(1 1 2 3 4 4 6 6);
@Value_1 = qw(a a a a a a a a );
@Value_2 = qw(b b b b b b b b );
@Value_3 = qw(c d c c c d c d);


##</code><code>##

if (($Entry > 0) && ($ID[$Entry] eq $ID[$Entry - 1])) {
		
if ($Value_1[$Entry] =~ m/($Value_1[$Entry - 1])/) {
			
$Placeholder = join(' / '$Value_1[$Entry], $Value_1[$Entry - 1]);

delete $Value[$Entry - 1];
push(@Value, $Placeholder);
			
	etc...		}