THE ILLUSION OF LINEARITY. “But that does not necessarily mean that the complexity of the output increases linearly. The complexity is defined as the minimum number of gates needed to do a job; not the number of gates in some particular setup.”
https://onlinelibrary.wiley.com/doi/full/10.1002/prop.201500092?casa_token=8OO3b1OY4e4AAAAA%3ARqriAgTwtxnvsxl09CqnNy79m7l4ye7ZrkZxcLtObB9kHsTwYgzBuIV2X-xXQ7ezoR6VQPfQLCS-vnI