anchor.diff:  
   objectClass: definedObjectClass | objectClassDefn | parameterizedObjectClass ;
   
  -objectClassDefn: 'CLASS' '{' fieldSpec (',' fieldSpec)* '}' withSyntaxSpec? ;
  +objectClassDefn: 'CLASS' OPENACCOL fieldSpec (',' fieldSpec)* CLOSEACCOL withSyntaxSpec? ;
   
   withSyntaxSpec: 'WITH SYNTAX' syntaxList ;
   
  
positive.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 ;
  
negative.code: textInteger: IDENITIFIER ;
  
  /** Enumeration Type */
  enumeratedType: ENUMERATED OPENACCOL enumerations CLOSEACCOL ;
  
  enumerations
  	: rootEnumeration
  