y = next(x,init);
The next function allows you to make constructs like:
x(k+1) = x(k) - 0.1 + u(k)
where k is the kth sample. Using the next function, this can be entered in 20-sim as:
next(x,0) = x - 0.1 + u;
x and y will become discrete signals. 20-sim will automatically detect the existence of discrete signals. Each chain of discrete signals will be assigned a specific sample time. You can set this sample time to any desired value in the Simulator (choose Properties, Simulation and Discrete System).