I want to also add that while I would never make the case that breath power is aiki, it can be part of it. I also would not limit kokyu to breath. Hence why I said I could make the argument that kokyu was part of that list I put up of his quotes. If we consider intent and ki to make aiki in us then breath training is part of that, but also something that can be added to that. Intent, Ki, aiki, breath power in training and or delivery of aiki (or jins). So we can say how does part of breath power make kokyu-but also be different and how can kokyu involve heaven/ earth/ man?
Sorry reread earlier posts , question answered
Intent was one of my next guesses