Beyond that, dotted lists are introduced via the undefined example (a b . c), which requires one to go even further and make a second assumption (namely, assume the intention was to refer to (a . (b . c)), then assume the quoted transformation rule applies to certain non-lists allowing that to be rewritten as (a b . c)).
Since the document does use list in ways that encompass dotted lists and goes out of its way to define proper lists, we can infer that list includes dotted lists. Also, it's a long-running convention that the term "proper X" implies there are other kinds of X's.
Like I said, I'm confident your interpretation is the intended one. But you cannot prove it as such, and that's where we disagree.
