anchor.diff:  
   valueAssignment :
         type
  -      ASSIGN_OP
  +      '::='
          value
   ;
   
   type :
  -    (builtinType | referencedType) ( constraint | sizeConstraint )? (L_BRACE namedNumberList R_BRACE)?
  +    (builtinType | referencedType) ( constraint | sizeConstraint )? ('{' namedNumberList '}')?
       ;
   
   builtinType :
  
positive.code:     | 'TEXTUAL-CONVENTION'
      | 'NOTIFICATION-GROUP'
      | 'AGENT-CAPABILITIES'
      | INTEGER_LITERAL ((L_BRACE  R_BRACE))?
      | 'BITS'
      ;
  
  
negative.code:     ;
  
  imports :
      ('IMPORTS' symbolsImported ';'? )?
      ;
  
  symbolsImported
  