PIPELINE STOP

          The symbol STOP is used to control whether the  Pipeline  actions  run
    unattended, or require a user input.  In Widget mode, symbol STOP is defined
    by  default  as  being  command PAUSE, requiring user input to continue.  In
    pure pipeline mode (PIPELINE *  command), symbol STOP  is  defined  as  CON-
    TINUE, so that action proceed without any user intervention.

      The user may override these default behviours by defining STOP either as
      SYMBOL STOP CONTINUE
    or
      SYMBOL STOP PAUSE
    before pipeline actions.