.rs .sp 2.5i .ce100 AT&T Bell Laboratories Murray Hill, New Jersey 07974 .sp|4.25i Computing Science Technical Report No. 163 .sp .ft B .ps 12 The IX Multilevel-Secure \s-2UNIX\s0 System .ps 10 .sp .ft I James A. Reeds M. Douglas McIlroy .ce 0 .sp |8.5i .in 0 .ft R January 1992