On Fri, Dec 3, 2010 at 12:10 AM, Raymond Hettinger
<report@bugs.python.org> wrote:
..
> Try not to sprawl this all over the docs.  Find the most common root and document it there.
> No need to garbage-up Fractions, Decimal etc. with something that is of zero interest to
> 99.9% of users.

Decimal do already has a big BNF display with

digit          ::=  '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'

And a note that, btw, "Other Unicode decimal digits are also permitted
where digit appears above. These include decimal digits from various
other alphabets (for example, Arabic-Indic and Devanāgarī digits)
along with the fullwidth digits '\uff10' through '\uff19'."

http://docs.python.org/dev/library/decimal.html#decimal-objects

Builtin int() doc take you on a link chase that ends at the language
reference int literal BNF.   Bringing these all to a common root was
exactly the reason I brought up these related modules.