my @useless = map { 1 } qw( this is a silly test );
print "@useless\n";

##</code><code>##

my @set1 = qw (apples oranges pears mangoes);
my @set2 = qw (bananas mangoes papayas coconuts);
my %first_set;
@first_set{@set1} = ();
my @union = grep { exists $first_set{$_} } @set2;