Brands credentials use this single show, and multiple show
credentials. It's based on the representation problem which is the
generalisation to multiple bases where Schnorr is one base, Pedersen
Commitments are two bases, Representation problem is n>2 bases.
The method used would work for Schnorr
Micha I think you are correct, I dont think extension blocks (or
sidechains for that matter) can allow soft-fork increase of the total
Bitcoins in the system, because the main chain still enforces the 21m
coin cap. A given extension block could go fractional, but if there
was a run to get out, the