Map over namedtuple keys and values: confusing error

General Usage
6

There a multiple ways of mapping a NamedTuple, depending on whether you want the result to be

  1. inferred,
  2. also NamedTuple,
  3. with the same keys, or different ones (ie whether those are mapped, too).

Please provide an MWE, with the desired input and output, for your specific use case.