Build new empty hash 'output'
Build a list of keys from longest to shortest
For each key in the list
   If key not a fragment of a key in the output hash
       Add key to output hash

##</code><code>##

my %phrase_counts = (
          'rendition' => '3',
          'automation' => '2',
          'saturation' => '3',
          'mass creation' => 2,
          'automation technology' => 2,
          'automation technology process' => 3,
          'technology process' => 5,
          'automation process' => 2,
);