{ Define how access may proceed to the segment.

  TYPE
    mmt$segment_access_state = (
      mmc$sas_allow_access,     { - The normal state. All access is allowed.
      mmc$sas_inhibit_access,   { - Indicates that any access
                                { to this segment from the task should wait.
                                { This happens because the job needs to perform
                                { recovery for this file.
      mmc$sas_terminate_access);{ - Indicates that a segment access condition
                                { should be raised On any access to the segment.

