KEYNOTE 4: For the same fundamental reason, the efficiency of a perfect, ideal Carnot cycle (being below 100%) would also be logically inappropriate (as if there are “some work losses” in the ideal reversible cycles). For the same reason as for the Heat pump cycle, it should be called the ‘Carnot cycle COP’, not the ‘Cycle efficiency’. Fundamentally, all ideal, reversible cycles must be “equally and maximally [100%] efficient,” as reasoned by Sadi Carnot [1].