I have a question about op_ctv related to the requirement to specify the
number of inputs. I don't quite see why its necessary, but most
importantly, I don't see why we want to *require* the user of the op to
specify the number of inputs, tho I see the reasoning why one would want to
specify it. If the op allowed both cases (specifying a number of inputs and
allowing any number), it seems like the best of both worlds. I started a
discussion on bitcointalk.org:

https://bitcointalk.org/index.php?topic=5220520