[r6rs-discuss] [Formal] Plausible alists

[AndrevanTonder]

On Tue, 24 Oct 2006, Michael Sperber wrote:

> Andre van Tonder <andre at het.brown.edu> writes:
>
>> Slight defect in plausible alist description.
>>
>> Description:
>> ------------
>>
>> Point 1 does not check that (car x) is a pair as is done in point 3.
>
> Could you elaborate on why it should?  The first two items simply
> codify that, even if n is 0, some minimal checking is done on the
> alleged plausible alist.  (Maybe I'm missing something trivial---this
> stuff makes my head spin.)

To be consistent with point 3, which does check that the first element is a 
pair.  However, I see that the concept "plausible alist up to n" is never even 
used in the specification of any of the procedures, which brings up another 
question:  Why is this definition even given?  One could instead of "up to n" 
define just the simpler "plausible alist of length n", where the issue does not 
arise since the first point would be dropped.

By the way, why is the name "p" introduced (but not used) in point 3 ?

Cheers
Andre