Re: [IEEE 1788]: Post-ballot comment
On 2015-02-12 08:05:38 +0100, Oliver Heimlich wrote:
> Am 12.02.2015 um 02:45 schrieb Vincent Lefevre:
> >On 2015-02-11 20:58:23 +0100, Oliver Heimlich wrote:
> >>In Table 10.7 (page 38) the 10th state of the interval overlap function is
> >>called “equal”. However, in the figure on page 39, line 8, it is called
> >>“equals”.
> >>
> >>I suggest to fix the definition in the table and call it “equals” for two
> >>reasons:
> >>1. This would be consistent with the other states, e.g., starts, finishes.
> >
> >There would be a drawback. The other states have the forms:
> >Xs and XedBy (except for "before" and "after", which are also
> >paired, but named differently). But "equal" is different: it is
> >the only state self-symmetric. If you name it "equals", then one
> >could think: where is the "equaledBy" one? So, this would not be
> >so consistent.
>
> The equal state describes an equivalence relation on the set of non-empty
> intervals and is therefore symmetric. The other states (except bothEmpty)
> are not symmetric.
>
> Would one expect it to be not symmetric and look for its inverse?
What I mean is that the "s" in "contains", etc. indicates an asymmetry
(there's a subject and a complement, and the verb links them in one
direction). For instance, there's "contains" for one relation, and
"containedBy" for the "opposite" one. With "equal", one would say that
two sets are equal, without a subject/complement asymmetry.
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)