On Wed, September 5, 2012 08:47, Andries van Renssen wrote: (01)
> In any relation (of any arity) the related things play roles of different
> kinds that are specific for the kind of relation.
> The semantics of the kind of relation depends on the roles that the
> related things play in the relation.
> An explicit specification of roles is required to define the semantics.
> This is independent of the sequence of arguments in an expression.
> If you don't make those roles explicit, then you have find an alternative,
> such as the sequence of the arguments (as in <is between on path>).
> Their sequence becomes a pseudo specification of the kinds of roles in the
> definition of the meaning of the relation. (02)
Well said. However, note that in a relation such as isBetweenOnPath,
that multiple arguments are equivalent for a bidirectional path. (03)
> Furthermore, the inverse expression has a different sequence of arguments,
> and is also a valid expression of the same fact. (04)
Inverse relations are redundant information. Some languages like them
because using them makes things easier for their reasoners. Other
languages, e.g. Cyc, discourage them as being redundant. If inverse
relations are defined in Cyc, Cyc makes one relation primary and converts
all statements using one into statements using the other. Queries using
the non-canonical form are converted to the canonical form, answers are
computed, and converted back to the form of the query. (05)
> Therefore, semantically it is purer to explicitly specify the kinds of
> roles. (06)
This requires reifying the statement of relation and ensuring that all
necessary statements for encoding the relation are asserted. Using a
higher-arity relation obviates the necessity for reification and guarantees
that none of the roles are accidentally omitted. (07)
> Therefore, a basic semantic structure for the expressions of facts could
> be:
> * kind of relation - kind of role - related thing (08)
Actually, you need
* reified relation - kind of role - related thing (09)
Without the reification you can not determine that the individual
arguments have anything to do with each other. (010)
> For an n-ary relation you need n such expressions. (011)
and an n+1st expression that the reified relation is an instance of
kind of relation. (012)
Reification allows one to make additional statements, such the time
period for which the statement is valid. (013)
> The form
> * related thing - kind of relation - related thing
> is just a short cut for a pair of such expressions, (014)
Actually, three. One has to identify the reified relation as being
an instance of kind of relation. (015)
> in which the kinds of
> roles are assumed to be known from the definition of the kinds of
> relation.
> This short cut is only suitable for binary relations and needs a mechanism
> to determine which role is played by the left hand thing and right hand
> thing respectively. (016)
Agreed, provided that reification is included. (017)
> A semantic model of the definition of a kind of relation requires even
> more detailed relations. (018)
More relations that are detailed; yes. Ones that are "more detailed";
i don't see that. (019)
> Such a model requires the specification of which kinds of roles are
> required by which kind of relation and
> which kinds of things may play such a role.
> This implies expressions such as:
> * kind of relation - required played - kind of role
> * kind of role - required player - kind of thing (020)
Of course, this can be done with n-ary relations, as Cyc has done for
over 15 years. (021)
> Note that the individual relations and roles are not yet explicit in these
> expressions. The basic semantic structures that I developed includes also
> the individual roles and relations and allows for the short cut
> expressions
> (see http://www.gellish.net/topics/semantic-modelling.html). (022)
> Each of these triples requires the expression of auxiliary facts, such as
> their intention (illocutionary force), author, dates, context, etc.
> In my view it is therefore not a question whether facts can be expressed
> in triples, but whether triples are a suitable structure
> when we in practice always model in collections of triples. (023)
Another question is whether triples are an efficient structure. (024)
> The Gellish Data Table is a universal structure for all these kinds of
> expressions, including the expression of auxiliary facts. That table is an
> alternative to RDF (with some creativity it can be converted into
> collections of triples if you like). It is described in the document
> "Definition of Universal Semantic Databases and Data Exchange Messages"
> on http://www.gellish.net/downloads/category/2-english.html. (025)
> Andries
>
>
> -----Oorspronkelijk bericht-----
> Van: ontolog-forum-bounces@xxxxxxxxxxxxxxxx
> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] Namens doug foxvog
> Verzonden: woensdag 5 september 2012 6:02
> Aan: [ontolog-forum]
> Onderwerp: Re: [ontolog-forum] Accommodating legacy software
>
> On Tue, September 4, 2012 17:02, Kingsley Idehen wrote:
>> On 9/4/12 3:41 PM, doug foxvog wrote:
>>> On Tue, September 4, 2012 12:34, Kingsley Idehen wrote:
> ...
>
>>>> I believe Data denotes Subject Observation.
>>>> I believe all observations are comprised of:
>>>> 1. a subject
>>>> 2. subject attributes
>>>> 3. subject attribute values.
>
> ...
>>> One common type of observation is that A is between B and C.
>>> How would you express this with a single triple? 8)#
>
>> I would state that A is between B. A is Between C. Then I would define
>> the semantics of the 'Between' predicate .
>
> !??
> Let's explore this:
> (and
> (between 10 5 11)
> (between 10 4 11)
> (between 10 6 11)
> (between 10 7 11))
> Using the KI translator this becomes:
> AND
> 10 is between 5
> 10 is between 11
> 10 is between 4
> 10 is between 11
> 10 is between 6
> 10 is between 11
> 10 is between 7
> 10 is between 11.
>
> What semantics does the between predicate have?
>
> How about the quaternary predicate, isBetweenOnPath?
> Can you express the following with triples:
>
> (and
> (isBetweenOnPath WashingtonDC Maryland Virginia I95)
> (not (isBetweenOnPath WashingtonDC Maryland Virginia I495)))
>
>
> -- doug foxvog
> ...
>>
>> Kingsley
>>>
>>> -- doug foxvog
>
>
>
> _________________________________________________________________
> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
> Shared Files: http://ontolog.cim3.net/file/
> Community Wiki: http://ontolog.cim3.net/wiki/
> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
>
>
> (026)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J (027)
|