On 19 Nov 2022, at 01:35, Shiro Kawai <xxxxxx@gmail.com> wrote:

> That part is resolved by the replies to my post.  Sensible base cases can be defined, and it makes sense to have them taking zero arguments.

Can you formally define them and show that they are a correct base case, in the sense of being of null effect if appended to the end of another arguments list? I can observe how the sample implementation behaves (emergently) when given no comparator arguments, but I’m still far from certain that they’re correct in a compositional sense.

>> If it would really help, I will change this, although all it would do is split four sentences into four bullet points with nearly identical  – it’s not one big run-on sentence, much as I do have a tendency to write those.
>
> I think it helps.  For example, the first sentence of make-product-comparator says "a comparator which compares ..."; but the defining term used in srfi-128 comparators is "equality predicate" and "ordering predicate", so it is clear to define "compare" in terms of those predicates.

Okay, I will do this.

Arthur, could the last call be extended a few days while I/we work out the details of the issue with no arguments passed to make-{sum,product}-comparator?

Daphne