anchor.diff:  annotation
   	:	ANNOTATION
   	;
  -
  -classRef
  -	:	type
  -	;
  -	
  -memberRef
  -	:	identifier
  -	;
   	
   type
   	:	( aPackage DOT )? simpleType
   	;
   	
  +wildcardType
  +	:	( aPackage DOT )? wildcardSimpleType
  +	;
  +	
   aPackage
   	:	identifier ( DOT identifier )*
   	;
  
positive.code: 	:	identifier
  	;
  	
  alias		// aliases cannot have wildcards
  	:	identifier
  	;
  
negative.code:  *   inherited from a super class.
   */
  
  // COMPILATION UNIT
  
  compilationUnit
  