Re: [P-1788]: Anything else to be said about interval overlapping?
Baker, Juergen, and p1788
I agree with the general outlines of this motion
However I have three comments
1) I appreciate that the interval comparisons are defined at
level 1 level in Table 1.
But i dislike that special cases specification are
addressed in subsequent notes.
I understand that such notes are very useful to explain
the behavior of the comparison not as as a additional definition.
IMHO such a approach is required because only order
relation between real numbers are involved in the definition of Table 1.
Both the conditions a \in A and a \notin Ashould be
used
As an example the before relation could be written
A \before B <=> \exists a'
\in A \wedge a' \notin B
\wedge
\exists b' \in B \wedge b' \notin A
\wedge
\forall a (\n A ) \forall b (\in B) a < b
2) IMHO the comparison meets and overlaps ( and consequently
metBy and overlappedBy ) should be merged .
I understand that from a mathematical point of view
the relations must distinguished.
This is clearly established by the Allen's work and
subsequent works on temporal reasoning .
An additional example is provided by the layout
example pointed out to the group by Nate Hayes
However in interval arithmetic, the bounds have to be
rounded. sup(A) is rounded upward, and inf(A) is rounded downward.
So the A meets B relation is restricted to the very
anecdotal case where in the mathematical model sup(A) and inf(B) are
equal floating point numbers.
3) a detail : The headers width(A) < width(B), width(A) =
width(B) and width(A) > width(B) are not appropriate for the columns
of table 2
Remark
While at the first glance the argument of comment 2 could be
also applied to the relation starts, finishes, and similar , this is
not true
since the bound shared by the interval are rounded in the
same way.
Bests regards,
Dominique
Ralph Baker Kearfott a écrit :
P-1788 members:
I have noticed that Motion 21.2 is under discussion until
November 21, at which time we will begin a vote. Is anything
else to be said about this motion before it is frozen and
we begin voting on it? Also, Juergen, am I correct concerning
this motion's status?
Best regards,
Baker
--
Dr Dominique LOHEZ
ISEN
41, Bd Vauban
F59046 LILLE
France
Phone : +33 (0)3 20 30 40 71
Email: Dominique.Lohez@xxxxxxx