my $ar = [ [ 'a', ], [ 'b, 'c', ], ];
my $flat = flat( $ar );
print Dumper $ar, $flat;

##</code><code>##

$VAR1 = [
          [
            'a'
          ],
          [
            'b',
            'c'
          ]
        ];
$VAR2 = [
          \$VAR1->[0][0],
          \$VAR1->[1][0],
          \$VAR1->[1][1]
        ];