anchor.diff:      | LOCAL_ID
       ;
   
  -full_column_name (
  +full_column_name
       : (table_name '.')? id
       ;
   
   column_name_list_with_order
       : id (ASC | DESC)? (',' id (ASC | DESC)?)*
  +    ;
  +
  +column_name_list
  +    : id (',' id)*
       ;
   
   cursor_name
  
positive.code: DIRECTORY_NAME:                        D I R E C T O R Y '_' N A M E;
  DISABLE:                               D I S A B L E;
  DISABLED:                              D I S A B L E D; 
  DISABLE_BROKER:                        D I S A B L E '_' B R O K E R;  
  DYNAMIC:                               D Y N A M I C;
  EMERGENCY:                             E M E R G E N C Y; 
  EMPTY:                                 E M P T Y;
  
negative.code: 
  default_value
      : NULL
      | DEFAULT
      | constant
      ;
  
  