[r6rs-discuss] Re: Plausible list problems

[AndrevanTonder]

On Tue, 3 Oct 2006, William D Clinger wrote:

> Although it is undecidable whether a list is
> plausible, the draft R6RS requirement can be
> implemented because it *requires* an exception
> to be raised if list is not a plausible list,
> while *allowing* an exception to be raised even
> if list is a plausible list.

Understood.  However, the following statements in the document are in
conflict, either directly or in spirit, with these statements:

p. 123:

"Consequently, procedures like length are only required to
  confirm that a list argument is a plausible list."

    - undecidable

p. 124:

"This section clarifies the domains of procedures in the base
  library and the (r6rs lists) library."
"These are clarifications to the domains of the procedures of
the base library described in sections 9.12, 9.15, and 9.18:"

   - misleading, since what is being clarified is not the
     domain, but some superset of the domain (e.g., the domain
     of map is some unspecified subset of the set of plausible
     lists).

p. 125:

"These are clarifications to the domains of the procedures
of the (r6rs lists) library described in chapter 12:"

    - ditto

Cheers
Andre