use strict;
use warnings;

my @a = 'A' .. 'E';
use Data::PowerSet 'powerset';
my $sets = powerset({ min => 3 }, @a);

foreach my $b (@$sets) {
  print join('', @{$b});
}
__END__
ABCDE *
BCDE  *
ACDE
CDE   *
ABDE
BDE
ADE
ABCE
BCE
ACE
ABE
ABCD  *
BCD   *
ACD
ABD
ABC   *