anchor.diff:  
   /*
    * Clinical Quality Language Grammar Specification
  - * Version 1.3 - May 2018 STU3 Ballot
  + * Version 1.3 - STU3 Publication
    */
   
   import fhirpath;
  
positive.code:     | 'timezone'
      ;
  
          pluralDateTimePrecision
      : 'years' | 'months' | 'weeks' | 'days' | 'hours' | 'minutes' | 'seconds' | 'milliseconds'
      ;
  
  
negative.code:     :
      libraryDefinition?
      usingDefinition*
      includeDefinition*
      codesystemDefinition*
      valuesetDefinition*
      codeDefinition*
      conceptDefinition*
      parameterDefinition*
      statement*
      ;
  
  /*
   * Definitions
  