Chris, (01)
you wrote:
> Hi Ed,
>
> Late delivery is a common business feature in financial contracts, such as
> foreign exchange.
> I have always treated the contract as describing a possible world - which
> might be actual - and a late delivery (and a partial late delivery) as a
> counter-part (in the actual world) of the delivery. (This is a solution you
> indicate below).
> In the case of your late shipment, doesn't the comment cash out as any
> actual shipment made after now that is a counter-part of the
> contracted/agreed shipment will be late. In this case, nothing changes
> state. (02)
To be clearer, the conceptual shipment may acquire an
instance/counterpart when it originally goes on the schedule, i.e., when
it is created as an object pursuant to an order under a contract. At
that point it has a number of properties -- the supplier, the customer,
the quantity, the item, the order and the expected delivery date. Once
the manufacturer fulfills the order by making and shipping the parts, it
acquires additional properties -- a container, a related carrier, a
carrier contract, etc., and it starts to acquire real 'states', notably
location at time. All of this can be handled by ordinary relations, a
few of which are ternary. But it becomes "late" when the delivery date
passes and the delivery has not happened. The business rules are
written in terms of a class called 'late shipment', which can be defined
in terms of other properties of a shipment, with a bit of trickery for
the 'time is past' relation. But the shipment does not satisfy the
class predicate when it is created. It comes to satisfy the class
predicate precisely via the trickery for 'time is past'. And the
recovery actions could involve substitute shipments and reassignment of
some other properties of the original shipment. We can and do timestamp
all these decisions and changes. The problem is the relationship of the
whole knowledge about the shipment to certain predicates and other
relations, which are both true and false if you don't specify a time
interval. The problem is that they resemble other propositions about
the shipment that are constant -- true or false for all time -- because
they refer to intrinsic/essential properties of the shipment and not to
accidental properties. (03)
Put another way there are wffs that look like propositions and are of
four kinds:
- those that are constantly true or false over all (interesting) time
- those that explicitly refer to time and state and are thus constantly
true or false
- those that implicitly refer to time and explicitly refer to 'state',
like 'late shipment', for which we may have work-arounds
- those that cannot be evaluated because they refer to state without time (04)
I would like to disallow the last group, because there is no meaningful
semantic model for them, but I don't know how to characterize them. And
the problem is that when you inject time concepts into a knowledge base
that was originally about instantaneous decisions, you find
'propositions' like that, primarily in rule antecedents. (05)
> Maybe our knowledge of the world changes states - however, as I said
> in an earlier mail on this thread, that is epistemic.
> (06)
This has nothing to do with epistemics. The knowledge being processed
is what we have recorded as "fact", and any relationship to the "real
world" is dependent on unmodeled factors. It is possible that the
shipment is really in Baltimore, even though we have recorded that it is
in Memphis. Handling correction to the knowledge base is a different
problem. (07)
(We do have a project dealing with capturing assertions from
supply-chain messages from multiple sources in IKL and evaluating their
consistency and credibility, but that is an entirely different issue.) (08)
> As you say, temporal words can sometimes be about temporal and modal
> relationships.
>
> EB> The 4D idea that a thing in a different state is a different thing,
>
>> and 'objects' are actually sequences (or more generally, lattices)
>> of things in states
>>
>
> Just to be clear, some 4D approaches build up the 4D objects from their
> states.
> However, I think it is often simpler to take the objects as just 4D
> simpliciter. If one wants to consider their states, then these are temporal
> slices that are also 4D simpliciter.
>
> EB>, but it is totally out of
>
>> line with the intuition of the domain experts.
>>
>
> Jubien starts his book on properties with several examples of 4D talk in
> everyday natural language. There seems to be a growing consensus that talk
> about events and processes are naturally 4D. The first half of the football
> match, etc. I'm sure football referees intuitions can stretch to first
> halves.
> (09)
People have no problem with the idea of happenings in time, and states
of the world in time. No one has a problem with models of Chris
Partridge, or a shipment, playing a role in a proposition that describes
a situation and refers to time. The intuition failure is the model of
states of an individual thing in time. They don't think of Chris
Partridge, or a shipment of goods, as a 'situation' in time. (010)
-Ed (011)
> Chris
>
>
>> -----Original Message-----
>> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
>> bounces@xxxxxxxxxxxxxxxx] On Behalf Of Ed Barkmeyer
>> Sent: 21 January 2011 18:39
>> To: [ontolog-forum]
>> Subject: Re: [ontolog-forum] Ontology of Rough Sets
>>
>>
>>
>> Christopher Menzel wrote:
>>
>>> On Jan 21, 2011, at 9:46 AM, doug foxvog wrote:
>>>
>>>
>>>> ...
>>>> A standard distinction between a set and a class, is that membership
>>>> in a [set] cannot change, while membership in a class can.
>>>>
>>>>
>>> I think it's useful to distinguish two claims when it comes to the
>>>
> identity
>
>> conditions of classes:
>>
>>> (1) Classes are not extensional (i.e., distinct classes can have the
>>> same members/instances)
>>>
>>> (2) Classes can change their membership.
>>>
>>> In the formal semantics of a number of KR languages, (1) is true but,
>>>
> strictly
>
>> speaking at least, (2) is not. Notably, classes in OWL are explicitly
>>
> non-
>
>> extensional: since a class is stipulated only to *have* an extension in
>>
> OWL's
>
>> formal semantics, nothing prevents distinct classes from having the same
>> extension. The same is true of RDF. However, simply because there is no
>> formal notion of change built into OWL's semantics, there is no
>>
> possibility,
>
>> within a given interpretation, that a class change its membership. As
>>
> noted
>
>> in an earlier message in this thread, without augmenting the notion of an
>> OWL interpretation somehow, change can only be represented formally in
>> terms of something like a series of interpretations that are thought of as
>> temporally ordered. That said, (2) does seem to be a strong *intuitive*
>>
> idea
>
>> in the KR, AI, and database communities.
>>
>> The particular problem I have recently got involved in is the intrusion of
>> temporal concepts into would-be ontologies in business applications.
>> In the supply-chain area, for example, it is important to be able to talk
>>
> about
>
>> schedules and shipments being "late". Getting past the indexical issues,
>> which are fixed by translating the intuitive "now"
>> into specific time relationships, the particular problem is that shipments
>>
> and
>
>> orders do change state, and actions are taken on the basis of
>>
> reclassification.
>
>> A major problem for us is that the industry folk throw these concepts into
>> what was an ontology for the "snapshot" model of decision-making -- the
>> state of the world at the time the decision is to be made. This gives
>>
> rise to
>
>> formalizing ideas like "proposition X is false at time A and true at time
>>
> B."
>
>> And that problem arises from the idea that states of things are
>>
> characterized
>
>> by propositions, which seems to be fundamental to applications of
>> ontologies. The 4D idea that a thing in a different state is a different
>>
> thing,
>
>> and 'objects' are actually sequences (or more generally, lattices) of
>>
> things in
>
>> states, is a means of producing a formal semantics, but it is totally out
>>
> of
>
>> line with the intuition of the domain experts. They cannot then
>>
> "validate"
>
>> the ontology -- they don't understand it.
>>
>> I have said in that forum that solving the problem is beyond my expertise.
>>
> It
>
>> is my conviction that the problem is not really "time", but rather "change
>>
> of
>
>> state" or "alternative states", and in that sense, "time" is a means of
>>
> labeling
>
>> "alternative possible worlds".
>>
>> All we are saying is that the intuitive notion of change is endemic to a
>>
> lot of
>
>> ontology applications. We can usually constrain the immediate application
>> to avoid the problem or create a convenient work-around, but that usually
>> means that the next application the business wants to use the ontology for
>> requires re-writing it.
>>
>> -Ed
>>
>> "Mathematicians are like Frenchmen. Whatever you say to them they
>> translate into their own language and at once it becomes something
>> entirely different."
>> -- Goethe
>>
>>
>>
>>> Finally, the idea that sets are extensional and classes are not is
>>>
> definitely
>
>> not standard among logicians and mathematicians, who typically associate
>> the notion of class with theories like VNBG, wherein both classes and sets
>> are extensional.
>>
>>> -chris
>>>
>>>
>>>
>> --
>> Edward J. Barkmeyer Email: edbark@xxxxxxxx
>> National Institute of Standards & Technology
>> Manufacturing Systems Integration Division
>> 100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
>> Gaithersburg, MD 20899-8263 Cel: +1 240-672-5800
>>
>> "The opinions expressed above do not reflect consensus of NIST,
>> and have not been reviewed by any Government authority."
>>
>>
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>
> (012)
--
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 Cel: +1 240-672-5800 (013)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (014)
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