anchor.diff:      ;
   
   startTransactionCharacteristic
  -    : WITH CONSISTENT SNAPSHOT
  -    | READ (WRITE | ONLY)
  +    : WITH CONSISTENT SNAPSHOT | READ (WRITE | ONLY)
       ;
   
   rollback
       : ROLLBACK WORK? 
       (
           (AND NO? CHAIN)? (NO? RELEASE)? 
  -       |TO SAVEPOINT? ID
  +       | TO SAVEPOINT? ID
       )
       ;
   
  
positive.code: import MySQLKeyword, Keyword, BaseRule, DataType, Symbol;
  
  setTransaction
      : SET (GLOBAL | SESSION) TRANSACTION
      setTransactionCharacteristic (COMMA setTransactionCharacteristic)*
      ;
  
  setTransactionCharacteristic
      : ISOLATION LEVEL level
      | accessMode
      ;
  
  level
      : REPEATABLE READ
      | READ (COMMITTED | UNCOMMITTED)
      | SERIALIZABLE
      ;
  
  accessMode
  
negative.code:     ;
  
  beginWork
      : BEGIN WORK? | startTransaction
      ;
  
  startTransaction
  