Proposed - for ternary relations in reference create two relations - R-at-all-times, R-at-some-time about bfo HOT 3 OPEN

From [email protected] on May 25, 2012 10:27:50

At the May 25 teleconference it was decided that we will review each of the ternary relationships and decide on a case by case basis whether to create an at-all-times, at-some-times, or both relationships. Chris pointed out that it may be able to prove, e.g., that quality-of-at-some-time is equivalent to quality-of-at-all-times. Alan pointed out that choice varies between relation and inverse, so quality-of-at-all-times, but has-quality-at-some-time.

Mathias, Chris, Alan, Ron will review the relations and propose what the choice should be

Status: Accepted
Owner: [email protected]

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From [email protected] on June 05, 2012 20:35:27

A realization: The inverse properties need to have their scope done differently.

Consider a part-of-at-all-times b
-> forall(t) exists_at(a,t) -> exists_at(b,t) and part_of(a,b,t)

The inverse of this is:
-> forall(t) exists_at(a,t) -> exists_at(b,t) and has_part(b,a,t)

But this is not necessarily the same as a has-part-at-all-times b, which
-> forall(t) exists_at(b,t) -> exists_at(a,t) and has_part(b,a,t)

It should be the case that r(a,b) <-> inv(r)(b,a)

However in cases where a and b exist over different temporal regions this will not hold.

I'm not sure what a desirable solution should be yet. Two obvious ones are to make clear the properties are not inverse of one another and define additional properties that are, or to use the anonymous inverse relation in OWL.

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From [email protected] on June 05, 2012 21:09:16

Ron Rudnicki has submitted his review (see comment 1) and offers (after a clarification of the FOL expansion of the relations) that both -at-some-time and at-all-time versions of the relations can be included.

Mathias has submitted his review. Comments of mine in line are marked as <<AR: >>.

((c-part-of c-has-part) :ternary) for both: at some times & at all times

((c-ppart-of c-has-ppart) :ternary) for both: at some times

<<AR: Why not the same as c-part-of>>

((m-part-of m-has-part) :ternary) [for both: at some times [if the b in a member_part_of b is defined by extension (which I think is not the case for BFO), then, of course, for the has-member-part it is: at all times]
<<AR: I realize I don't quite grok m-part-of and I believe the latest reference draft makes some changes, so I will review further>>

((located-in at some times & at all times has-location) :ternary)
<<AR: I read this as both at-some-time and at-all-times versions should be created for both relations>>

((located-at-r at some times r-location-of) :ternary)
<<AR: I read this as located-at-r and r-location-of are both to be defined as at-some-time>>

((inheres-in at all times bearer-of at some times) :ternary)

((s-dep-on has-s-dep at all times) :ternary)
Maybe I got that wrong, but the ref states:
" Inherence is a subrelation of s-depends on which holds between a dependent continuant and an independent continuant. Since dependent continuants cannot migrate from one independent continuant bearer to another, it follows that if a s-depends on independent continuant b at some time, then a s-depends on b at all times at which a exists. Inherence is in this sense redundantly time-indexed."
this seems to be wrong since some dependent continuants CAN migrate: they are generically dependent.

<<AR: Generic dependents are disjoint from specific dependents and there is no dependent continuant class (reference typo - will report), so there is no error as suggested. However I also question some of the logic. Inherence is a subrelation of s-depends and so it doesn't seem one can conclude what is concluded for the superproperty based on the subproperty.
I think Mathias' intention is that s-dep-on is suggested to be at-all-time and has-s-dep is at some times(please verify). If inherence is redundantly time indexed perhaps a reference issue should be added. Simply make the relation binary.

There may be a need for at-all-times version of has-versions of specific dependence and subproperties to capture cases such as mass and other physical properties for which there is a single instance that persist for the entire lifetime of the entity. See http://hl7-watch.blogspot.com/2008/02/weight-of-baby.html >>

((g-dep-on has-g-dep) :ternary) at some times
((q-of at all times has-q at some times) :ternary)
((f-of has-f) :ternary) analogues to quality
((r-of has-r) :ternary) analogues to quality
((d-of has-d) :ternary) analogues to quality

((has-material-basis material-basis-of) :ternary) analogues to quality
<<AR: This one I'm not sure of - need to better understand the relation. Examples needed>>

((concretizes concretization-of) :ternary)
given the elucidation:
" a(concretizes)[Elucidation: a concretizes b at t means: a is a specifically dependent continuant & b is a generically dependent continuant & for some material entity c, a s-depends on c at t and b g-depends on c at t, and if b migrates from bearer c to another bearer d than a copy of a will be created in d. [075-001]
I assume that "a copy of a" is a' viz. another instance, right?
In that case the relation holds at all times

<<AR: By this logic it is concretization-of that should be at-all-times. I think if one were be chosen for concretizes it would be -at-some-times. I'm not sure if the language of migration is the best choice for g-dependence - will consider putting in reference issue>>

((st-projects-onto-s s-projection-of-st) :ternary)
((has-participant participates-in) :ternary) at some time

<<AR: I assume that at-some-time is the choice for both cases. However for the participant case, earlier discussion (i should hunt for reference, but I think it originate with David OS) suggested that continuous participation was also a desired relation.>>

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