Deprecation of that form is a subject encompassing all for-loop constructs
and is not specific to this PEP. Also, most people are not aware that those
forms are even possible, so it is prudent to not even bring it up as that
would inevitably increase the number of people trying it in their code.
* Add claim to minimize use of lambda.
* Remove details of proposed new accumulator functions.
* Reference Jeff Epler's proof-of-concept patch.
* Minor wording improvements everywhere.