I got it working by using a difference in head lift. Build a series of liquid storages, one on top of the other; hook them up in series. Connect fresh water to the bottom of the tower. Make sure that the fresh water line doesn’t have enough head lift to fill the highest container (you can move your pumps back or make the tower taller to do this). Connect waste water to the tower, with plenty of head lift. When the water level is below the limit of the fresh pump, both fresh water and waste water can enter the tower, and it gradually increases. When the water level is above the limit, fresh water stalls but waste water can still enter, and the water level decreases. As a result, the water level hovers around the limit, and your machines can keep running.
A simpler method with just limiting fresh input with a valve will stop working if the machines aren’t producing constantly, since the pumps will keep bringing in fresh water and fill the pipe when the machines are idle.
That’s not how copyright works (at least not in the US). when a corporation creates a copyrighted work (by way of paying the person(s) that actually made it), the duration is set as 120 years after creation or 95 years after publication. The lifetime of any employee is not taken into account. When a copyright is made by a person, it lasts until 70 years after that person dies. You cannot swap out that person for someone else, even if the owner of the copyright changes.
You are probably thinking of a method that is used to make private agreements last basically forever. A private contract technically isn’t allowed to last forever, there has to be some point of expiration. To make a contract last forever anyway, they pick some condition that probably won’t happen for a ridiculous amount of time, such as when the last descendant of the king of England dies (I assume they use this because the royal family keeps good genealogy records). If a currently living person is required, they might pick some infant relative to make it last as long as possible.