sub add_set
{ # adds a set if it's unique, otherwise does nothing.
my ($mhash, $new_hashid, @elements) = @_;
my %endhash;
foreach my $element (@elements)
  {$endhash{$element} = 1;}
my @matched_keys = grep
	{
	my $truth = 1;
	foreach my $cand_element (keys %endhash)
		{$truth *= defined $mhash{$_}{$cand_element}; }
	}
	(keys %$mhash); # This only ensures that we have a subset
my $magic_key;
foreach my $matched_key (@matched_keys)
  {
  my $match_ok = 1;
  foreach my $c_elem (keys %{$mhash{$matched_key}} )
    {
    if(! defined($endhash{$c_elem}) )
      {$match_ok = 0;}
    }
  if($match_ok) {$magic_key = $matched_key;last;}
  }
if(defined($magic_key) )
  {
  # Our set is already in here, so just return
  print "Set already found, returning\n";
  return;
  }
$$mhash{$new_hashid} = \%endhash; # Otherwise, add it
}