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