<pre>
connector InputInteger = input Integer;

connector OutputInteger = output Integer;

block Controller

InputInteger x;

OutputInteger Integer w;

...

end Controller;

block Plant

InputInteger u;

OutputInteger y;

...

end Plant;

class System

Controller k;

Plant p;

equation

connect(p.y, k.x);

connect(k.w, p.u);

end System;

</pre>