anchor.diff:  
   xMLNumberForm: NUMBER ;
   
  -xMLNameAndNumberForm: IDENITIFIER '(' xMLNumberForm ')' ;
  +xMLNameAndNumberForm: IDENITIFIER OPENPAR xMLNumberForm CLOSEPAR ;
   
   relativeOIDType: 'RELATIVE-OID' ;
   
  -relativeOIDValue: '{' relativeOIDComponentsList '}' ;
  +relativeOIDValue: OPENACCOL relativeOIDComponentsList CLOSEACCOL ;
   
   relativeOIDComponentsList: (relativeOIDComponents)+ ;
   
  
positive.code: 
  EXTENSIONDEFAULT: 'EXTENSIBILITY IMPLIED' | ;
  
  
  // TODO: value definition
  // TODO: type definition
  
  
  
negative.code: 	| [\x000E1000-\x000EFFFD] ;
  
  // chapter 12.2 Type references
  TYPEREFERENCE: UPPERCASE (ALPHANUMERIC | '-' ALPHANUMERIC)* ;
  
  // chapter 12.3 Identifiers
  IDENTIFIER: LOWERCASE (ALPHANUMERIC | '-' ALPHANUMERIC)* ;
  
  // chapter 12.4 Value references
  VALUEREFERENCE: IDENTIFIER ;
  