anchor.diff:      ;
   
   textualConventionAssignement :
  -    ASSIGN_OP 'TEXTUAL-CONVENTION' (complexAttribut COMMA*)+
  +    '::=' 'TEXTUAL-CONVENTION' (complexAttribut ','*)+
       ;
   
   trapTypeAssignement :
       'TRAP-TYPE'
  -     (complexAttribut COMMA*)+
  -      ASSIGN_OP
  +     (complexAttribut ','*)+
  +      '::='
         integerValue
       ;
   
   objectTypeAssignement :
       'OBJECT-TYPE'
  -     (complexAttribut COMMA*)+
  -      ASSIGN_OP
  +     (complexAttribut ','*)+
  +      '::='
         value
       ;
   
   macroAssignement : 
  -    'MACRO' ASSIGN_OP 'BEGIN' macroContent+ 'END'
  +    'MACRO' '::=' 'BEGIN' macroContent+ 'END'
       ;
   
   macroContent:
  -    IDENTIFIER 'NOTATION'? ? ASSIGN_OP macroVal+ ( '|' macroVal+ )*
  +    IDENTIFIER 'NOTATION'? ? '::=' macroVal+ ( '|' macroVal+ )*
       ;
       
   macroVal:
  
positive.code:     ;
  
  imports :
      ('IMPORTS' symbolsImported SEMI_COLON? )?
      ;
  
  symbolsImported
  
negative.code: 
  objIdComponents 
      : NUMBER
      | IDENTIFIER ('(' NUMBER ')')?
      ;
  
  integerValue :
  