Suppose we have two users ['] and [ ], and a single printer . Both users print their results on this printer . Since there is only a single printer...

In this question, what does U1(U2) mean? Does that mean U1 is using the printer or U2?

29 .Suppose we have two users ['] and [ ], and a single printer . Both users print theirresults on this printer . Since there is only a single printer , only one user can print a job ata time. Suppose we have the following atonic propositions for U'] and [12 .Un req" ("LIZ.req" ` Indicates that LI ( LUIZ ) requests usage of the printer .U1 . use " (" LIZ . use" \ : Indicates that U'I ( LUTZ ; uses the printer .*UI release" (" LIZ. release"` Indicates that LI IVIZ ) releases the printer*LISE PLIL to specify the following properties ."a. Mutual exclusion . only one user at a time can use the printer . ( AP)6 . Finite time of usage : a user can print only for a finite amount of time . ( IP )c. Absence of starvation . if a user wants to print something . he'she eventually is able todo so. ( IP )`. Alternating access : users must strictly alternate in printing . [ OF ]