#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

sub potset {
    my @set = @{shift(@_)};

    if (@set == 0) {
    return [[]];
    }
    else {
    my @ps = @{potset([@set[1..$#set]])};

    return [(map { my @l = @$_; push @l, $set[0]; [@l]; } @ps), @ps];
    }
}

print Dumper(potset(\@ARGV));