anchor.diff:      | write_
       | quit_
       | halt_
  +    | hang_
       | new_
       | break_
       | do_
  -    | (CLOSE | ELSE | GOTO | HANG | IF | JOB
  -    | KILL | LOCK | MERGE | OPEN | READ | TCOMMIT
  +    | kill_
  +    | (CLOSE | ELSE | GOTO | IF | JOB
  +    | LOCK | MERGE | OPEN | READ | TCOMMIT
       | TRESTART | TROLLBACK | TSTART | USE | VIEW | XECUTE)
       ;
   
  
positive.code:     ;
  
  halt_
      : (HALT1 | HALT2)
      ;
  
  write_
      : (WRITE1 | WRITE2) SPACE* arglist
      ;
  
  quit_
      : (QUIT | 'Q')
      ;
  
  new_
  
negative.code:     : G O T O
      ;
  
  HALT
      : H A L T
      ;
  
  HANG
  