my @numbers                 =
                            (
                          ['|'] ,
                        ['|','|'] ,
                      ['|','|','|'] ,
                    ['|','|','|','|'] ,
                  ['|','|','|','|','|'] ,
                ['|','|','|','|','|','|'] ,
              ['|','|','|','|','|','|','|'] ,
            ['|','|','|','|','|','|','|','|'] ,
          ['|','|','|','|','|','|','|','|','|'] ,
        ['|','|','|','|','|','|','|','|','|','|'] ,
                           ) ;
                         foreach
                      ( @numbers )
            { print scalar @$_; print "\n"; }

##</code><code>##

2;0 juerd@ouranos:~$ perl -e'undef christmas'
Segmentation fault
2;139 juerd@ouranos:~$