use strict;no warnings;
   sub CHECK{
       # Who knew? CHECK blocks get called after compilation,
       # before execution!  See perlmod

       @~ = $~ =~ m~(.)~g;

          # @~ is a valid but odd array name, eh?
          # $~ is the default output file handle, "STDOUT"
          # and so @~ = qw(S T D O U T)

       unshift @~, splice @~, 2, 3;

          # rearrange @~ to qw(D O U S T T)

       unshift @~, pop @~, *{H};

          # rearrange further: pop@~ is "T", and *{H}
          # is "*main::H" (which would yield a warning)
          # so @~ is now qw(T *main::H D O U S T)

       push @~, *{PAR};

          # now @~ is qw(T *main::H D O U S T *main::PAR);

       ($~[$#{~}],$~[$#{~}+-1])=($~[$#{~}+-1].$/=>$~[$#{~}]);

          # that gibberish swaps the last two elements, and
          # then appends a newline to the (new) last element,
          # so @~ is qw(T *main::H D O U S *main::PAR T\n);

       for(@{~}){

          s~.*:~~;

             # delete "*main::", leaving qw(T H D O U S PAR T\n)

          s~$~ ~ if ($?++%2)

             # append a space to each odd element, so we have
             # ("T", "H ", "D", "O ", "U", "S ", "PAR", "T\n ")
       }
   }
   die 'TILDE', @~;

      # die with @~ in scalar form:
      #   [TILDE][T][H ][D][O ][U][S ][PAR][T\n ]
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