​​Dear all,

The issue 326 is old. I made some slides (dated 31/3/2017) which can be found at

http://www.edd.uio.no/download/cidoc_crm/issue-326-overview-and-thoughts-HW.pptx


The exchange of emails has two topics:

1) E18 Physical Thing as a subclass of E92 Spacetime Volume

​2) the properties P4 and P160


**********

1: In my opinion it is model theoretically correct that E18 Physical Thing​ as 
a subclass of E92 Spacetime Volume. However, it may be confusing for persons 
not so interested in theory.  Therefor we could introduce a property Pxx E18 
Physical Thing <->  E92 Spacetime Volume with the cardinality (1,1:0,1) 
describing the the (model theoretical) fact that  a part of  E18 Physical Thing 
is in a 1-1 correspondence with a subset of E92 Spacetime Volume​.


The model will still have the same explanatory power, and hopefully be more 
intuitive for the lay persons.


***********

2:

In the slides I give the following comment:



"The cardinality of P4 has time-span is (1,1:1,n), that is, two or more 
instances of E2 Temporal Entity can “share” an instance of E52 Time-span. This 
was introduced in an early stage to model simultaneity.

This way of modeling simultaneity is considered obsolete and the cardinality of 
P4 should be (1,1:1,1)-

E2 Temporal Entity and E52 Time-span in a one to one relation

E2 Temporal Entity and E92 Spacetime Volume  in a one to one relation. "



Please, note that  P4's cardinality states that every instance of P4 is 
connected to one and only one instance of E52 Time-span. Therefore, the number 
of instances of E52 Time-span will be equal or less than the number of 
instances of E2 Temporal Entity.



The number of instance of E92 Spacetime Volume and E2 Temporal Entity will 
always be equal due to the cardinality (1,1:1,1) of P160  has temporal 
projection.  E4 Period is a subclass of E92 Spacetime Volume and has less than 
or equal number of instances. The cardinality of P160 when lowered to

P160: E4 Period <-> E52 Time-span

must have the more strict cardinality  (1,1:0,1), that is, it is an injection 
of E4 Period into E52 Time-span. There may exist instances of E52 Time-span 
which are not related to an instance of the subclass E4 Period

Correspondingly:

P4: E4 Period <-> E52 Time-span

must have the cardinality constraint (1,1:0,n).

The scope note of P160:

“This property describes the temporal projection of an instance of an E92 
Spacetime Volume. The property P4 has time-span is the same as P160 has 
temporal projection if it is used to document an instance of E4 Period or any 
subclass of it.”

So the formulation discussed in the emails is already there.

The scope note of P4:

 “This property describes the temporal confinement of an instance of an E2 
Temporal Entity. The related E52 Time-Span is understood as the real Time-Span 
during which the phenomena were active, which make up the temporal entity 
instance. It does not convey any other meaning than a positioning on the 
“time-line” of chronology. The Time-Span in turn is approximated by a set of 
dates (E61 Time Primitive). A temporal entity can have in reality only one 
Time-Span, but there may exist alternative opinions about it, which we would 
express by assigning multiple Time-Spans. Related temporal entities may share a 
Time-Span. Time-Spans may have completely unknown dates but other descriptions 
by which we can infer knowledge.”

The formulation “A temporal entity can have in reality only one Time-Span, but 
there may exist alternative opinions about it, which we would express by 
assigning multiple Time-Spans.” should be deleted. Such multiple assignment due 
to uncertainties or alternative opinions is the case for many properties in CRM.

In my opinion “Related temporal entities may share a Time-Span.” Should also be 
deleted and the cardinality of P4 (E2 Temporal Entity <-> E52 Time-span) made 
stricter to (1,1:1,1).


________________________________
From: Crm-sig <crm-sig-boun...@ics.forth.gr> on behalf of Martin Doerr 
<mar...@ics.forth.gr>
Sent: 12 March 2019 11:09
To: ste...@paveprime.com; 'George Bruseker'
Cc: 'crm-sig'
Subject: Re: [Crm-sig] Issue 326 Resolving inconsistencies between E2, E4, E52 
and E92

Dear Steve, George,

Your arguments well taken, I may remind you that the argument was not only a 
1:1 relation.

It contained 4 elements:

a) a 1:1 relation
b) a common identity condition: The identity of the STV depends on the identity 
of the phenomenon
c) There existence conditions are identical: the one exists where and as long 
as the other
d) Properties do not interfere.

The condition d) becomes more tricky with the question of the time spans, as 
you have seen. Here, the question for me is not ontological, but of the logical 
formalism. As I have shown, it can be described in FOL. It is the only 
complication we have. We just declare two properties to be identical downwards.

The alternative you are advocating for is:
a) Fill the database with a very large number of necessary 1:1 links: events 
are some of the the most frequent items we have.
b) You have not solved anything wrt P160, because P4 is still the same as P160 
in these cases, and the path of correspondence is even more confusing.

So, we just buy in a much more confusing schema, to my opinion. The schema is 
what we use on a daily base. Discussing CRM extensions is not the end-users 
interest, but the task of the SIG.

I believe we cannot avoid entering some complexity here in our discussions, and 
resolve it giving priority to the end-user schema.
I think the first arguments should be, if the final schema is confusing, and if 
the alternative is less confusing.

I am not sure where to publish adequately the above reasoning. It should be 
somewhere buried in the minutes. But we tried very hard to make the things 
clear in the scope notes of E4, E18.

What do you think?

All the best,

Martin


On 3/11/2019 10:29 PM, Stephen Stead wrote:
I am with George on this.
The fact that substantial things have a 1:1 relationship with an STV does not 
warrant the E92 superclass status IMHO.
It makes for horrible confusion and lots of “special case” rules and ………….
Please let us avoid this.
Rgds
SdS


Stephen Stead
Tel +44 20 8668 3075
Mob +44 7802 755 013
E-mail ste...@paveprime.com<mailto:ste...@paveprime.com>
LinkedIn Profile https://www.linkedin.com/in/steads/

From: Crm-sig 
<crm-sig-boun...@ics.forth.gr><mailto:crm-sig-boun...@ics.forth.gr> On Behalf 
Of George Bruseker
Sent: 11 March 2019 19:52
To: Martin Doerr <mar...@ics.forth.gr><mailto:mar...@ics.forth.gr>
Cc: crm-sig <Crm-sig@ics.forth.gr><mailto:Crm-sig@ics.forth.gr>
Subject: Re: [Crm-sig] Issue 326 Resolving inconsistencies between E2, E4, E52 
and E92

Dear all,

To wade into the muddy waters, I would venture that having E92 as superclass of 
E4 and E18 is finally something that may just create confusion. It is not 
actually the case that a thing IS its space time volume. A thing necessarily 
HAS a STV so long as it is substantial, but the things we say about the STV of 
a thing and what we say about the thing itself are distinct. The convenience we 
get from making E92 the super class of E18 and E4 seems to come at the price of 
this confusion, and the ability to put temporality on physical things directly, 
something we have tried to avoid. If we do however remain committed to it 
having this superclass status, then it seems we should have to put in some 
instructions on how you are able and not able to use the properties that it 
lends downwards to its children classes.

Best,

George


------------------------------------------------------
Dr. George Bruseker
Coordinator

Centre for Cultural Informatics
Institute of Computer Science
Foundation for Research and Technology - Hellas (FORTH)
Science and Technology Park of Crete
Vassilika Vouton, P.O.Box 1385, GR-711 10 Heraklion, Crete, Greece

Tel.: +30 2810 391619   Fax: +30 2810 391638   E-mail: 
bruse...@ics.forth.gr<mailto:bruse...@ics.forth.gr>
URL: http://www.ics.forth.gr/isl


On Mar 9, 2019, at 1:37 PM, Martin Doerr 
<mar...@ics.forth.gr<mailto:mar...@ics.forth.gr>> wrote:

Dear Robert,

In the first place, E2 has a substance of "phenomena" something "becoming" 
"changing" "moving", "interacting". In addition, we interpret it now also more 
statically as including a sort of maintaining something. It is necessarily 
connected to some "things" on which such interactions, changes or temporary, 
non-essential formation of properties happen, but we have seen so far no good 
general way to describe the ways of involvement at the level of E2.

E92 is nothing of that kind. It is just spacetime, the generalized space in 
which we live and think, not what is there not what happens there. It is just a 
"where". It is further a volume in that space, i.e., it must have some inner 
part, and a surface as fuzzy as it may be, and a way to identify it.

We connect E4 and E18 with E92 as second superclass in order to describe a 
necessary one-to-one combination, in order to save the trivial links between 
them. We could do that with E2 too, but the space in which things like "being 
married" occur can hardly be seen as volumes with a surface. In contrast, I can 
be in the meeting (E4) or outside, in the battle or outside, even though the 
fuzziness between being inside and outside is very high.

Therefore, I would exclude both, E2 being subclass of E92 or superclass.

The discussion to which degree we should regard any E18 as ongoing interactions 
in spacetime is old and endless. We have so far rather preferred to think of a 
fundamental difference between "becoming" and "being" as a psychological and 
linguistic phenomenon, because this is the most adequate to the way people 
document things. The problem now is that by introducing E92 we are again 
confronted with the borderlines between the change itself and the changing 
thing, the thing that persists over time, but yet is limited in time, the 
things that are somewhere, but constitute a "where" for others.

Would that make sense:-)?

Best,

Martin

On 3/7/2019 11:35 PM, Robert Sanderson wrote:

Hi all,

I’m sure there’s a good reason why this is not a good idea, and if I had been 
at the meetings since the early days I surely would know why it’s not a good 
idea … but …

Could E92 not be a sub class of E2, if we were to separate out E3 Condition 
State in the work to model States / Phases more thoroughly?
Then P160 could just be deprecated in favor of P4?  P10, P132 and P133 are all 
still valuable, as they include the intersection of space as well as of time.

My first thought was that the properties of E2 other than P4 are not applicable 
to E18 (and descendants) … but if P160 is, and P132/P133 are, then there must 
be some temporality that can have a start and end, as given in the temporal 
projection.   The temporal projection of Rob starts after the start of the 
temporal projection of Rob’s mother seems like a reasonable thing to assert, if 
we can have timespans/temporal projections.

Rob


From: Crm-sig 
<crm-sig-boun...@ics.forth.gr><mailto:crm-sig-boun...@ics.forth.gr> on behalf 
of Martin Doerr <mar...@ics.forth.gr><mailto:mar...@ics.forth.gr>
Date: Saturday, March 2, 2019 at 9:43 AM
To: crm-sig <Crm-sig@ics.forth.gr><mailto:Crm-sig@ics.forth.gr>
Subject: [Crm-sig] Issue 326 Resolving inconsistencies between E2, E4, E52 and 
E92

Dear All,

We consider the following properties:

P4 has time-span (is time-span of)
Domain:              E2 Temporal Entity
Range:                E52 Time-Span
Quantification:    many to one, necessary, dependent (1,1:1,n)

P160  has temporal projection (is temporal projection of)
Domain: E92 Spacetime Volume
Range: E52 Time-Span
Quantification: one to one (1,1:1,1)


In FOL:


P4(x,y) ⊃ E2(x), P4(x,y) ⊃ E52(y)
P160(x,y) ⊃ E92(x), P160(x,y)⊃ E52(y)
The problem comes from this: E4 Period being a spacetime volume and a temporal 
entity.
E4(x) ⊃ E2(x), E4(x) ⊃ E92(x)
I now propose to: declare P4, to imply P160  from E4 Period "downwards":
(P4(x,y) ∧E4(x)) ⊃ P160(x,y), (P160(x,y) ∧E4(x)) ⊃ P4(x,y).
We may then recommend to use only P4 from E4 Period downwards.
I do not know, if we would also need (P160(x,y) ∧E4(x)) ⊃ P4(x,y) in order to 
make them identical from E4 downwards.
================================================
Further:
P7 took place at (witnessed)
Domain:              E4 Period
Range:                E53 Place
Quantification:    many to many, necessary (1,n:0,n)
"The related E53 Place should be seen as a wider approximation of the geometric 
area within which the phenomena that characterize the period in question 
occurred, see below."

P161 has spatial projection (is spatial projection of)
Domain: E92 Spacetime Volume
Range: E53 Place
Superproperty of: E18 Physical Thing. P156 occupies (is occupied by): E53 Place
Quantification: one to many, necessary, dependent (1,n:1,1)
Firstly, I believe the quantification of P161 must be Quantification:    many 
to many, necessary (1,n:0,n). A place needs not be the projection of a 
Spacetime Volume.
Then, in FOL:
P7(x,y) ⊃ E4(x), P7(x,y) ⊃ E53(y)
P161(x,y) ⊃ E92(x), P161(x,y) ⊃ E53(y)
I propose to add: The spatial projection of an E4 Period is a "took place at".
(P161(x,y) ∧E4(x)) ⊃ P7(x,y).
Opinions?
Best,
Martin


--

------------------------------------

 Dr. Martin Doerr



 Honorary Head of the

 Center for Cultural Informatics



 Information Systems Laboratory

 Institute of Computer Science

 Foundation for Research and Technology - Hellas (FORTH)



 N.Plastira 100, Vassilika Vouton,

 GR70013 Heraklion,Crete,Greece



 Vox:+30(2810)391625

 Email: mar...@ics.forth.gr<mailto:mar...@ics.forth.gr>

 Web-site: http://www.ics.forth.gr/isl


--

------------------------------------

 Dr. Martin Doerr



 Honorary Head of the

 Center for Cultural Informatics



 Information Systems Laboratory

 Institute of Computer Science

 Foundation for Research and Technology - Hellas (FORTH)



 N.Plastira 100, Vassilika Vouton,

 GR70013 Heraklion,Crete,Greece



 Vox:+30(2810)391625

 Email: mar...@ics.forth.gr<mailto:mar...@ics.forth.gr>

 Web-site: http://www.ics.forth.gr/isl
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--
------------------------------------
 Dr. Martin Doerr

 Honorary Head of the
 Center for Cultural Informatics

 Information Systems Laboratory
 Institute of Computer Science
 Foundation for Research and Technology - Hellas (FORTH)

 N.Plastira 100, Vassilika Vouton,
 GR70013 Heraklion,Crete,Greece

 Vox:+30(2810)391625
 Email: mar...@ics.forth.gr<mailto:mar...@ics.forth.gr>
 Web-site: http://www.ics.forth.gr/isl

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