jim rozen writes:

I suggest you go back and re-read the entire thread
and find any other reference to perpetual motion.

You're the perpetual motion advocate. You assert that an expanded quantity
of air represents the same energy as the compressed equal quantity out of a
reservoir, the difference "remains in the tank". But the compressed form
can be made into the expanded, with a yielding of more energy, which is by
defintion a perpetual motion device.