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  Description:
 
    A subsystem is defined to be a specified program within an application,
    plus any subprograms subsequently called by programs already in the
    subsystem that do not already belong to any other subsystems.
 
    With function-code = 0
 
      This function declares a subsystem. The routine returns a subsystem
      handle. If the program is not already loaded the function loads it.
      If an error occurs in finding or loading the program a subsystem
      handle of zero is returned.
 
      A program belonging to a subsystem will only be deallocated (that
      is, deleted from memory), when either it is canceled by the CANCEL
      verb, or the program cancels the entire subsystyem using
      function-code = 1, or the application executes a STOP RUN or CHAIN
      statement. The main program of a subsystem should not be canceled
      with the CANCEL statement unless all other programs in the subsystem
      have already been canceled.
 
    With function-code = 1
 
      This function cancels all programs in the specified subsystem. If
      any program in the subsystem is still active, that program is
      released from the subsystem and is not canceled.
 
      On exit RETURN-CODE = 0.
 
    With function-code = 2
 
      This function removes the program that called it from any subsystem
      the program is in. To ensure a program is never included in any
      subsystem, call this function at the start of each entry in to the
      program.
 
  Parameters on Entry:
 
    function-code               The subfunction number.
 
    With function-code = 0
       ss-name-len              The length of subsystem program-name field.
       ss-name                  The subsystem program-name (space-
                                terminated). This must be a COBOL .INT or
                                .GNT module.
 
 
    With function-code = 1
       ss-handle                The subsystem handle returned by a function
                                0 call.
 
    With function-code = 2
       dummy-param              value 0.
 
 
  Parameters on Exit:
 
    With function-code = 0
       ss-handle                The subsystem handle.
                                    -♦-