QUIT

        [SIC\]QUIT [ALL]

    When   typed  after  a  pause,   QUIT  aborts   the  execution   of  the
    interrupted level. QUIT returns an error to the previous level to signal
    this anomalous end.  The previous level  is  then  also  interrupted  to
    allow a complete error recovery. Note that this behaviour depends on the
    ON ERROR command.   QUIT  can  also  be  used  to  abort  FOR-NEXT  loop
    compilation.

    If argument ALL is present, all nested procedures are aborted,  and  SIC
    goes back to base level.

    In interactive sessions, QUIT should be used instead of BREAK and RETURN
    because  it  allows  extra  decision at run time. QUIT used as the error
    recovery command is equivalent to RETURN ERROR.