//minimum probability process enters the criticial section // only interested in the probability in states for which // - process is going to make a draw (draw1=1) // - no process is in the critical section (otherwise probability is clearly 0 // and we take the minimum value over this set of states Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical"}{min} ] // probability above is zero which is due to the fact that the adversary can use the values // of the state variables of the other processes // to demonstrate this fact we restrict attention to states where these values // are restricted,i.e. where the values of the bi variables are bounded Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical" & maxb<6}{min} ] Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical" & maxb<5}{min} ] Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical" & maxb<4}{min} ] Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical" & maxb<3}{min} ] Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical" & maxb<2}{min} ] Pmin=?[ !"one_critical" U (p1=2) {draw1=1 & !"one_critical" & maxb<1}{min} ] // liveness (eventially a process enters its critical section // since we have removed the loops this holds with probability 1 even without fairness Pmin=?[F p1=2 | p2=2 | p3=2 ]