anchor.diff:  open : Open;
   season : Season;
   unknown : Unknown;
  -uaSymbol : UASymbol;
   
   // *******************  Level 1: Interval Parser Rules  ********************* //
   
  
positive.code:     ;
  
  partialUncertainOrApproximate
  	: MonthDayKnownYearUA
  	| MonthDayKnownYearUAParenUA
  	| MonthKnownYearDayUA
  	| MonthKnownYearDayUAParenUA
  	| YearDayKnownMonthUA
  	| YearDayKnownMonthUAParenUA
  	| YearMonthKnownDayUA
  	| YearMonthKnownDayUAParenUA
  	| YearKnownMonthDayUA
  	| YearKnownMonthDayUAParenUA
  	| DayKnownYearMonthUA
  	| DayKnownYearMonthUAParenUA
  	| YearKnownMonthUA
  	| YearKnownMonthUAParenUA
  	| Level2YearMonthUA
  	| Level2YearMonthUAParenUA
  	| Level2YearMonthDayUA
  	| Level2YearMonthDayUAParenUA
  	| MonthKnownYearUA
  	| MonthKnownYearUAParenUA
      | SeasonUA
      ;
  
  
negative.code: 	| YearMonthUA | YearMonth
  	| YearMonthDayUA | YearMonthDay
  	;
  
  // **************************   Level 2: Tokens   *************************** //
  
  