input file name(PL/0 program file)?   test3.pl0
list object code  ?
   0 const  a=10;
   1 var  b,c;
   1 procedure  p;
   1   begin
   3     c:=b+a
   5   end;
   8 begin
   9  read(b);
  11  while  b#0 do
  15    begin
  15      call p; write(2*c); read(b)
  23    end
  23  end.
start pl0
?2
      24

?4
      28

?0