use strict;
use warnings;
use Set::Scalar;

my @array1 = qw(c d e);
my @array2 = qw(e f g h);
my @array3 = qw(a b d);
my @array4 = qw(s g h j k l);
my @metaArray = (\@array1, \@array2, \@array3, \@array4, );

for my $first (0 .. $#metaArray - 1) {
    for my $second ($first + 1 .. $#metaArray) {
        my (%union,  %intersect);
        $union{$_}++ && $intersect{$_}++
            foreach @{$metaArray[$first]}, @{$metaArray[$second]};
        
        my @intersect = sort keys %intersect;
        print "\@array$first, \@array$second: @intersect - ";
        print scalar @intersect, "\n";
    }
}