Hi,

#!/usr/bin/perl
use strict;
use warnings;

my @must_have=qw(abc def ghi);
my @to_check = @must_have[0,1];     # only the first two elements 
my %lookup = map {$_, 1} @to_check; # lookup hash

my $flag = 1; 
for (@must_have) {
  next if $lookup{$_}; 
  $flag = 0
}

print "flag not set" if not $flag
[download]

Regards,
svenXY