import some_component.dzn;

component some_system
{
  provides some_interface provided_port;
  requires some_interface required_port;
  system
  {
    some_component top;
    some_component middle;
    some_component bottom;
    provided_port <=> top.provided_port;
    top.required_port <=> middle.provided_port;
    middle.required_port <=> bottom.provided_port;
    bottom.required_port <=> required_port;
  }
}
