Re: Discussion of the term "interval", I have added a citation for the
term to my fork of the documentation of SRFI-122 found here:

https://github.com/gambiteer/srfi-122/

On 12/15/18 3:54 AM, Marc Nieper-Wißkirchen wrote:
> "Interval" as a technical term in mathematics is a connected subset of a
> linearly (= totally) ordered set.

I take it you're not using "connected" in the "arc-connected" or "cannot
be contained in the union of two disjoint open sets"-connected
topological sense.

> Cartesian products of intervals are usually not intervals (for some
> canonical order of the product set), so one shouldn't call things like
> {1, 2, 3} x {0, 1, 2} x {0} intervals. The name cuboid would be much better.

I've spent some time in the past few days reviewing what terms authors
have used for cross products of one-dimensional real, bounded, intervals
and found

cuboid
$d$-rectangle (in $d$ dimensions)
parallelepiped
box
cell

Some of these terms are already used in various programming languages.

Overall, I still prefer "interval" for the concept.

Brad