On Mar 25, 2017 12:17 AM, "Luke Dashjr via bitcoin-dev" <bitcoin-dev@lists.
linuxfoundation.org> wrote:

 Any ideas? :/


Can't the size be aggregated up the tree such that each midstate hash is
the hash of branches below plus the agreegate of the sizes below.

This would make the root  hash(left + right + size/weight) and the proof
would just be the preimage.