for my $k ( keys %harry ) {
   my $a1 = $harry{$k};
   my $a2 = $harry{$phash{$k}};

   my %delete_a1;
   my %delete_a2;

   OUTER:
   for $i1 ( 0 .. $#$a1 ) {
     #next if $delete_a1{$i1};  # Never true.

      for $i2 ( 0 .. $#$a2 ) {
         next if $delete_a2{$i2};
         next if $a1->[$i1] ne $a2->[$i2];

         $delete_a1{$i1} = 1;
         $delete_a2{$i2} = 1;
         next OUTER;
      }
   }

   @$a1 = map $a1->[$_], grep !$delete_a1{$_}, 0..$#$a1;
   @$a2 = map $a2->[$_], grep !$delete_a2{$_}, 0..$#$a2;
}