anchor.diff:     ;
   
   declarators
  -   : declarator (COMA declarator)*
  +   : declarator (COMMA declarator)*
      ;
   
   declarator
  
positive.code:    ;
  
  enum_type
     : KW_ENUM ID LEFT_BRACE enumerator (COMA enumerator)* RIGHT_BRACE
     ;
  
  enumerator
  
negative.code:    ;
  
  interface_inheritance_spec
     : COLON interface_name (COMMA interface_name)*
     ;
  
  interface_name
  