RE: [legalruleml] Time Instants or Time Points

["Adrian Paschke" <Adrian.Paschke@gmx.de>]

Hi Tara,

Yes, there are many existing ontologies and vocabularies/schemas available for time. Since there is nothing special about the representation of time in the legal domain which would require a domain-specific model, we should reuse them.

Reaction RuleML therefore has a generic approach which supports this reuse. There is a basic distinction in whether the temporal aspect are based on the relationships between "time instants" (type="ruleml:TimeInstant") or "time intervals" (type="ruleml:TimeInterval">). Depending on this core distinction a time becomes a linear continuous time model with points in time called "time instants"(<Time type="ruleml:TimeInstant">) or a discrete time interval model with "time points" (<Time type="ruleml:TimePoint">) as a relative time interval with an absolute reference or a relative reference to some given time interval. 

A duration is an amounts of time, .e.g. <ruleml:Time> <ruleml:Data xsi:type="xs:duration">P5Y2M10D</ruleml:Data> </ruleml:Time> or other quantities of duration values with other types of time units including nominal time units, e.g.3 years  <ruleml:Time><Ind iri="owl-time:Year">3</Ind><ruleml:Time> and discrete time functions (<ruleML:Time><Expr>).

<Interval> in Reaction RuleML is a generic concept for modeling intervals (Time/Spatial/Event/Action/Situation Intervals). Time intervals are then either based on the  segments of a linear continuum of time instants or the discrete time points (which span a smaller time interval).

Reaction RuleML also has a rich set of algebra operators for intervals (Allens relations such as During, Overlaps, ...) and general time arithmetic's and aggregators (such as Every, Timer, Any, ...-), and a general <Operator> (XML extension point) for adding further special operators from the many existing domain specific languages.

So, depending on whether the Legal RuleML collection is a set of time points it would be <lrml:TimePoints>  or <lrml:TimeInstants> in the case of time instants. 
I would propose to be more generic and say <lrml:Collection type="ruleml:TimePoint">, so that we can have different types of Collections.

-Adrian


From: legalruleml@lists.oasis-open.org [mailto:legalruleml@lists.oasis-open.org] On Behalf Of Tara Athan
Sent: Donnerstag, 18. Oktober 2012 01:02
To: legalruleml@lists.oasis-open.org
Subject: [legalruleml] Time Instants or Time Points

There is a relatively recent date-time ontology published by OMG (http://www.nist.gov/customcf/get_pdf.cfm?pub_id=911074) that addresses time scale granularity and also solves the problem of duration (is 1 month greater, equal or less than 30 days?)

While LegalRuleML is not supposed to be dependent on any particular ontology, this work does provide a useful conceptualization that allows certain intervals of time to be specified with a single datum. For example the date 2012-10-12 corresponds to a particular interval of time which can be specialized to a particular 24 hr interval when a timezone is added. This general concept of a point on a time scale with a particular granularity is called "time point". It is more general than a "point in time" or "time instant", but could include that concept if the time scale is continuous.

I proposed that we adopt this terminology, (but not the ontology) by referring to a collection of <ruleml:Time> elements as <lrml:TimePoints>

This also avoids the unfortunate plural "Times", which could be confused with multiplication or repitition, while retaining generality regarding the granularity, if any, of the time scale.

Example

<lrml:TimePoints>
  <ruleml:Time key="t1"> <ruleml:Data xsi:type="xs:dateTime">2012-07-21T00:00:00Z</ruleml:Data> </ruleml:Time>
  <ruleml:Time key="t2"> <ruleml:Data xsi:type="xs:date">2012-07-21</ruleml:Data> </ruleml:Time> </lrml:TimePoints>

Tara