Emacs Lisp Elements

Seems clear and useful. That said, there's nothing particularly bad or inaccessible about the actual Emacs Lisp manual: https://www.gnu.org/software/emacs/manual/html_mono/elisp.ht...

Or the official tutorial: https://www.gnu.org/software/emacs/manual/html_mono/eintr.ht... (which to be clear I haven't read, but have heard nice things about).

Of all the things for which emacs can be criticised, documentation rigor is really not one.

Agreed; Emacs is the gold standard for documentation. It comes with a reference manual (400k words), an Emacs Lisp reference (600k words), _and_ 64 other manuals for individual Emacs modes or features including one just for Calc mode (250k words), a manual just for Org mode (130k words), one for Gnus (180k words) etc. All told it adds up to about 2.6 million words of documentation.

Still, another manual written from a different perspective probably won’t hurt anything.

The Gnus manual in particular has certain whimsical Pratchett-esque charm to it that I love so much.

One reasons Prot himself was able to become a bonafide Emacs Guru in just a few years is because he's the kind of person who reads manuals. He speaks highly of the included docs, and often credits them for his knowledge.

The manual (https://www.gnus.org/manual.html) starts with:

> See what the critics say about the manual:

> “Often when I read the manual, I think that we should take a collection up to have Lars psycho-analysed.”

And he wasn’t even a programmer by trade. AFAIK he used to work in Brussels at the European Commission, he started using Emacs for his writing and taught himself Emacs Lisp as a first programming language, probably by diving deep into the Emacs manual.