block MarkovChain
//external function myrandom() returns a random real number in [0, 1]
parameter Integer x0 = 0;
parameter Integer xmax = 100;
OutputInteger x;
algorithm
when initial() then
x := x0;
elsewhen sample(0, 1) then
if (x < xmax)
then
   if (myrandom() <= 0.8)
   then
     if (myrandom() <= 0.9)
            then
            x := x + 1;   
            else
            x := max(0, x - 1); 
            end if;
     else
     x := max(0, x - 1); 
     end if;
end if;
end when;
end MarkovChain;