Each process P_i,i=1.....9 is coded as follows

  Repeat
  P(mutex){
  critical section
  }
  V(mutex)
  Forever

The code for P₁₀ is identical except that it uses V(mutex) in place of P(mutex). What is the largest number of processes that can be inside the critical section at any moment?

Given the following Pascal like program segment:

Procedure A;

     x,y:intger;

     Procedure B;

            x,z:real;

            S1

     end B;

     Procedure C;

            i:integer;

            S2;

     end C;

end A;

The variables accessible in S1 and S2 are

Heap allocation is required for languages.

$$\sum { = \left\{ {a,b} \right\},\,\,} $$ which one of the following sets is not countable.