#!/usr/bin/perl

use strict;
use warnings;
use Math::Combinatorics;

my @list = qw(Alpha Beta Caesar Delta);

for( 2 .. scalar(@list) ){
    my $comb = Math::Combinatorics->new(
        count => $_,
        data  => [@list],
    );
    
    while( my @perms = $comb->next_combination ){
        print join( ' ', @perms ), "\n";
    }
}

C:\>combinatorics.pl
Alpha Beta
Alpha Caesar
Alpha Delta
Beta Caesar
Beta Delta
Caesar Delta
Alpha Beta Caesar
Alpha Beta Delta
Alpha Caesar Delta
Beta Caesar Delta
Alpha Caesar Beta Delta