for (<DATA>) {
    chomp; split(/ => /);
    $hash{$_[0]} = $_[1];
}
$data[$#data+1] = [split(/ /, $hash{$_})]
    for (sort keys %hash);

print join("\t", sort keys %hash) . "\n";
for (0..(1<<$#data+1)-1) {
    $bin = sprintf("%0".($#data+1)."b", $_);
    for (0..$#data) {
        print $data[$_][substr($bin,$_,1)]."\t"
    } print "\n";
}

__DATA__
A => 0 1
B => 2 3
C => 4 5
X => 6 7
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