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