<pre>
connector InputInteger = input Integer;

connector OutputInteger = output Integer;

block C1

InputInteger u;

OutputInteger x;

...

end C1;

block C2

InputInteger u;

OutputInteger x;

...

end C2;

block C3

InputInteger u;

OutputInteger x;

...

end C3;

class System

C1 k1;

C2 k2;

C3 k3;

equation

connect(k1.x, k2.u);

connect(k2.x, k3.u);

connect(k3.x, k1.u);

end System;
</pre>