Time

Local identifier: xwkont:concept:time Slug: time Editorial status: reviewed Created: 2026-07-04 Modified: 2026-07-06

Scope Note

Selection rationale (per ADR-0018's admission bar and a decision that each 0.2.0-batch concept gets real rationale recorded as it is scoped, not backfilled): Time is the first concept selected from the 0.2.0 batch. It clears ADR-0018's ≥3-source threshold with the widest margin of any candidate in the batch — direct primary-source verification this session found a nameable temporal-region category in 6 of the 8 source ontologies (all except UFO and YAMATO; UFO's absence is a confirmed finding in the fetched 2021 paper and the OntoUML vocabulary fallback, while YAMATO's is confirmed only as an absence in the one YAMATO document that is actually fetchable, not asserted as a settled fact about YAMATO overall — see Uncertainty). This corrects docs/evaluations/foundational-ontology-concept-terms-matrix.md's "Observation 2," which had claimed only 5 sources (omitting SUMO and GUM, which this pass found do have Time content, and never checking GUM at all) — see that document's own updated Cross-Cutting Observation 2 and this crosswalk's Uncertainty section. Time is also methodologically load-bearing in a way none of the 8 already-reviewed concepts are: continuant-occurrent.md's own core split is defined in terms of time ("persisting... through time" vs. "unfolding... through time") without Time itself ever being crosswalked as its own concept until now.

This crosswalk compares each source ontology's own treatment of time-as-a-category — the region, quantity, or class denoting temporal extent, instant, interval, or duration — not any single source's full philosophy of time (e.g., BFO's SNAP/SPAN framework, GFO's Brentano-based continuum theory, or UFO's process-philosophy commitments are each much larger literatures than what is scoped here). Sources compared: BFO, DOLCE, SUMO, UFO, GFO, YAMATO, TUpper, GUM (per ADR-0015's 8-source scope).

Cross-cutting finding, established this session: there is no consensus across the 6 sources that have a Time category on what kind of thing Time is. BFO alone classifies its temporal region as a subtype of Occurrent — every other source that has a Time category treats it as independent of the occurrent/continuant (or equivalent) split entirely: DOLCE files it as an abstract region (a quality-space notion, the same branch as physical-region, neither endurant nor perdurant); SUMO files it under Abstract/Quantity, disjoint from Physical (where SUMO's Process sits); GFO gives it its own sui generis third top-level branch (Space_time, explicitly owl:disjointWith both Presential and Occurrent); TUpper makes timepoint one of four flat, co-equal top-level classes (alongside object/activity/activity_occurrence); GUM's Time has a dual parent (Substance and TemporalObject), an ancestor of neither its occurrent-like Process nor its continuant-like SimpleThing. This is the sharpest structural divergence found in this crosswalk — not a labeling difference but a genuine disagreement about where Time sits in each source's top-level architecture. See note-001.

Exclusions: this crosswalk does not address Spatial Region/Space (a separate 0.2.0-batch candidate, planned separately, though several sources — BFO's spatiotemporal region, GFO's Space_time — treat Time and Space as siblings under a shared parent, noted but not resolved here) or the Abstract-vs-Concrete split (also a separate 0.2.0 candidate, though SUMO's and GFO's classification of Time on the abstract/non-concrete side is directly relevant background — see note-001).

Core.ttl placement is deliberately left open at this draft stage. Per the same process the original 8 concepts followed (a class is added to data/ontology/core.ttl only once its crosswalk reaches reviewed, consistent with docs/governance/release-versioning-policy.md's MINOR = "reviewed crosswalk scope" definition), no xwkont-core:Time class exists yet. The cross-cutting finding above (5 of the 6 sources with a Time category — all except BFO — treat it as independent of Occurrent/Continuant) is a live open question for that eventual placement — see Uncertainty.

Labels, Alternate Labels, and Source Terminology

Role	Label or term	Source	Language	Notes
XwkOnt working label	Time	XwkOnt	en	Not yet in data/ontology/core.ttl — see Scope Note.
Source term	Temporal region (+ one-dimensional/zero-dimensional temporal region, temporal interval, temporal instant)	BFO	en	Subtype of Occurrent.
Source term	Temporal-region (+ time-interval)	DOLCE	en	Subtype of region, a quality-space notion — neither endurant nor perdurant.
Source term	TimeMeasure (+ TimeDuration, TimePosition, TimeInterval, TimePoint)	SUMO	en	Subtype of Quantity, on the Abstract side of SUMO's Physical/Abstract split.
Alternate label	(none found — see Uncertainty)	UFO	en	No class named Time/TemporalRegion/Instant/Interval; Time appears only as a property of Perdurant ("unfold in time").
Source term	Time (+ Space_time, Temporal_region, Chronoid, Time_boundary)	GFO	en	Its own sui generis top-level branch, disjoint from both Presential and Occurrent.
Alternate label	(not found in the fetchable material — see Uncertainty)	YAMATO	en	"Time"/"temporal"/"interval" occur only as ordinary undefined vocabulary in the one fetchable YAMATO document, never as a defined class.
Source term	Timepoint	TUpper	en	TUpper's only temporal class; instant-like, no interval/duration counterpart.
Source term	Time (+ TemporalObject, TimeInterval, TimePoint, and 14 further subtypes)	GUM	en	By far the richest treatment of any source; grounded in Halliday & Matthiessen's systemic-functional-linguistics theory of the clause, not a metaphysical persistence theory.

Source Definitions and Contextual Notes

Source	Term or identifier	Dimension	Claim type	Definition, quotation, or paraphrase	Reference	Locator	Notes
BFO	Temporal region (BFO_0000008)	technical	direct quotation	"(Elucidation) A temporal region is an occurrent over which processes can unfold." Subclass of Occurrent (BFO_0000003).	xwkont:ref:bfo-2020	verified: bfo-core.ttl, class BFO_0000008, fetched and read directly 2026-07-04	The only one of the 6 sources with a Time category that classifies it as occurrent — see note-001.
BFO	One-dimensional / zero-dimensional temporal region (BFO_0000038 / BFO_0000148)	technical	direct quotation	One-dimensional: "a temporal region that is a whole that has a temporal interval and zero or more temporal intervals and temporal instants as parts... The temporal region during which a process occurs." Zero-dimensional: "a temporal region that is a whole consisting of one or more separated temporal instants as parts... A temporal region that is occupied by a process boundary." Mutually owl:disjointWith.	xwkont:ref:bfo-2020	verified: bfo-core.ttl, fetched and read directly 2026-07-04
BFO	Temporal interval / temporal instant (BFO_0000202 / BFO_0000203)	technical	direct quotation	Interval: "a one-dimensional temporal region that is continuous, thus without gaps or breaks... The year 2018." Instant: "a zero-dimensional temporal region that has no proper temporal part... The millennium."	xwkont:ref:bfo-2020	verified: bfo-core.ttl, fetched and read directly 2026-07-04	BFO's own worked examples for interval/instant ("the year 2018"/"the millennium") appear swapped relative to ordinary usage (a millennium is longer than a year, and both examples describe a bounded span, not a durationless point) — recorded as found, not corrected, since the elucidation text is quoted verbatim from the primary source.
DOLCE	Temporal-region	technical	direct quotation	"A region at which only temporal qualities can be directly located. It assumes a metrics for time." Subclass of region; owl:disjointWith physical-region.	xwkont:ref:dolce-lite-owl	verified: DOLCE-Lite.owl, fetched and read directly 2026-07-04	Classified as a region (DOLCE's quality-space branch), not an endurant or perdurant — see note-001.
DOLCE	Time-interval	technical	direct quotation	"A temporal region, measured according to a calendar." Subclass of temporal-region.	xwkont:ref:dolce-lite-owl	verified: DOLCE-Lite.owl, fetched and read directly 2026-07-04	No time-instant/time-point class found in this module — DOLCE does not subdivide into instant/interval the way BFO does.
SUMO	TimeMeasure (+ TimeDuration, TimePosition)	technical	direct quotation	"The class of temporal durations (instances of TimeDuration) and positions of TimePoints and TimeIntervals along the universal timeline (instances of TimePosition)." Subclass chain: Entity → Abstract → Quantity → PhysicalQuantity → ConstantQuantity → TimeMeasure.	xwkont:ref:sumo-niles-pease-2001	verified: current Merge.kif, fetched and read directly 2026-07-04	Filed under Abstract, not Physical — a real divergence from BFO/DOLCE/GFO's occurrent-or-region framing; SUMO's Process (occurrent-like) sits on the opposite, Physical side entirely. See note-001.
SUMO	TimeInterval / TimePoint	technical	direct quotation	"An interval of time... this class contains only convex time intervals." / "An extensionless point on the universal timeline... it doesn't make sense to talk about how long a TimePoint lasts." (partition TimePosition TimeInterval TimePoint) — an exhaustive, disjoint partition of TimePosition.	xwkont:ref:sumo-niles-pease-2001	verified: Merge.kif, fetched and read directly 2026-07-04	This corrects docs/evaluations/foundational-ontology-concept-terms-matrix.md's prior claim that SUMO has no Time category — a depth-of-search miss in that document's shallower pass, not a real absence.
SUMO	TemporalRelation	technical	direct quotation	(subclass TemporalRelation Relation), (subclass TemporalRelation InheritableRelation) — reifies temporal relations (before, BeginFn, EndFn, temporalPart), distinct from the TimeMeasure branch above.	xwkont:ref:sumo-niles-pease-2001	verified: Merge.kif, fetched and read directly 2026-07-04	Filed under Relation, not Time — noted for completeness but not treated as this crosswalk's SUMO correspondence (that role belongs to TimeMeasure/TimeInterval/TimePoint). Already correctly filed under Relation in candidate-concepts.md.
UFO	(no class — property of Perdurant only)	technical	non-equivalence	"Perdurants are individuals that unfold in time accumulating temporal parts." No reified Time/TemporalRegion/Instant/Interval class is asserted anywhere in the paper.	xwkont:ref:ufo-2021	verified absence: 2021 Applied Ontology paper, already-extracted text re-searched 2026-07-04	The OntoUML vocabulary TTL (xwkont:ref:ontouml-vocabulary) was also checked as a fallback: zero occurrences of "time"/"temporal"/"interval"/"duration"; its begin/end are PropertyStereotype individuals (modeling-notation annotations), not temporal-region classes.
GFO	Time (+ Space_time)	technical	direct quotation	"The time model of GFO is based on Brentano and the glass continuum of Allen&Hayes." Space_time (rdfs:subClassOf Individual) is GFO's own third top-level branch, alongside Presential and Occurrent, all mutually owl:disjointWith. Time is rdfs:subClassOf Space_time, owl:disjointWith Space.	xwkont:ref:gfo	verified: modules/gfo-base.owl, fetched and read directly 2026-07-04	The only source among all 8 whose own primary text names a specific philosophical/formal lineage for its Time treatment — see note-002.
GFO	Temporal_region / Chronoid	technical	direct quotation	Temporal_region: "the mereological sum of chronoids, i.e. time regions may consist of non-connected intervals of time." Chronoid: "entities sui generis. Every chronoid has exactly two extremal and infinitely many inner time boundaries which are equivalently called time-points."	xwkont:ref:gfo	verified: modules/gfo-base.owl, fetched and read directly 2026-07-04	Chronoid's own gloss uses the phrase "entities sui generis" — GFO explicitly declines to reduce Time to either its Presential or Occurrent camp.
GFO	Time_boundary	technical	direct quotation	"Time boundaries depend on a chronoids (i.e. they have no independent existence) and can coincide." owl:disjointWith Temporal_region.	xwkont:ref:gfo	verified: modules/gfo-base.owl, fetched and read directly 2026-07-04	GFO's closest analog to BFO's temporal instant, formalized as a dependent boundary rather than a region in its own right.
YAMATO	(none found in the fetchable document)	technical	non-equivalence	"Time"/"temporal"/"interval" occur repeatedly but only as ordinary, undefined vocabulary (e.g. things "need time and space to exist"; "an action exists in an open interval... while an event exists in a closed interval") — never as a defined YAMATO class.	xwkont:ref:yamato-mizoguchi-2010	verified absence, scoped: 2010 technical report, full-text re-searched 2026-07-04	Scoped absence, not a flat claim about YAMATO overall — the OWL/Hozo files remain behind the hozo.jp registration gate and the 2022 paper remains blocked. See Uncertainty.
TUpper	Timepoint	technical	direct quotation	"(timepoint t) is TRUE in an interpretation of TUpper if and only if t is a member of the class of timepoints in the universe of discourse of the interpretation. Timepoints form a linear ordering." One of four flat, co-equal top-level classes (object/activity/activity_occurrence/timepoint).	xwkont:ref:tupper-colore	verified: TUpper-Terms.html, fetched and read directly 2026-07-04	TUpper's only temporal class — no interval/duration counterpart exists; timepoint denotes an instant-like entity in a linear order, not a region.
GUM	Time (+ TemporalObject)	technical	direct quotation	Time: "Time as a general undecomposable substance." rdfs:subClassOf both Substance and TemporalObject (dual parentage). TemporalObject: "The general concept of temporal objects, including all points, paths, volumes, undivided wholes, etc."	xwkont:ref:gum-owl	verified: GUM-31.owl, fetched and read directly 2026-07-04	Correction (2026-07-04, via space.md's research): Process is not an ancestor of Time, but SimpleThing is, several levels up — TemporalObject rdfs:subClassOf SpatialTemporal rdfs:subClassOf NonConsciousThing rdfs:subClassOf SimpleThing, confirmed by direct inspection of GUM-31.owl's NonConsciousThing block. The original claim above ("neither... is an ancestor") is incorrect as to SimpleThing and left here struck by this note rather than silently edited, per this repository's practice of recording corrections rather than erasing prior claims.
GUM	TimeInterval / TimePoint (+ Past, Present, Future, TemporallyBounded, TemporallyUnbounded, DurationInTime, InstantaneousInTime, OneOrTwoDTime, ThreeDTime, ProfilesAndStages, TemporalProfile, ZeroDTime)	technical	direct quotation	TimeInterval: "A time interval." TimePoint: "A time point." (owl:disjointWith each other.) DurationInTime: "A Configuration may be take time to unfold or be instantaneous (HM 1999: 471)."	xwkont:ref:gum-owl	verified: GUM-31.owl, fetched and read directly 2026-07-04	18 distinct classes total — by far the richest temporal apparatus of any of the 8 sources. Grounded in Halliday & Matthiessen's (1999) systemic-functional-linguistics theory of the clause, cited by page number directly inside multiple class definitions — modeling how a clause's tense/aspect/boundedness is grammatically realized, not time as a mind-independent feature of reality.
GFO/DOLCE/SUMO/TUpper/GUM	Independent-category convergence	philosophical	editorial observation	All 5 non-BFO sources with a Time category (DOLCE, SUMO, GFO, TUpper, GUM) each classify it as independent of their occurrent/continuant-equivalent split — a region, an abstract quantity, a sui generis branch, a flat top-level class, or a dual-parented class respectively — never as a subtype of their occurrent-like category. BFO alone subsumes Time under Occurrent.	xwkont:ref:bfo-2020, xwkont:ref:dolce-lite-owl, xwkont:ref:sumo-niles-pease-2001, xwkont:ref:gfo, xwkont:ref:tupper-colore, xwkont:ref:gum-owl	inference across six sources' own stated classifications, not a single cited passage making the comparison explicitly	See note-001; this is the crosswalk's central finding.

Source Ontology Correspondences

Correspondence ID	Source ontology	Source term	Source identifier or IRI	Source version	Reference	Inclusion rationale
xwkont:correspondence:time:001	BFO	Temporal region (+ one-/zero-dimensional, interval, instant)	BFO_0000008, BFO_0000038, BFO_0000148, BFO_0000202, BFO_0000203	BFO 2020 (directly verified 2026-07-04)	xwkont:ref:bfo-2020	Direct terminological and structural match; the only source classifying Time as occurrent.
xwkont:correspondence:time:002	DOLCE	Temporal-region (+ time-interval)	http://www.loa-cnr.it/ontologies/DOLCE-Lite.owl#temporal-region, #time-interval	DOLCE-Lite v397 (directly verified 2026-07-04)	xwkont:ref:dolce-lite-owl	Direct terminological match; included despite the region/quality-space classification diverging from BFO's occurrent classification.
xwkont:correspondence:time:003	SUMO	TimeMeasure (+ TimeDuration, TimePosition, TimeInterval, TimePoint)	TimeMeasure, TimeDuration, TimePosition, TimeInterval, TimePoint (SUMO/SUO-KIF term names are their own identifiers)	Current Merge.kif (directly verified 2026-07-04; not the 2001 Niles & Pease paper, which predates this branch)	xwkont:ref:sumo-niles-pease-2001	Corrects the matrix's prior "no SUMO Time category" finding; included as a structural analog despite sitting on the Abstract, not Physical, side.
xwkont:correspondence:time:004	UFO	(none)	not applicable — no class exists	Applied Ontology, 2021 (directly re-searched 2026-07-04)	xwkont:ref:ufo-2021	No correspondence recorded; UFO's only temporal content is Perdurant's own "unfold in time" property. See Uncertainty.
xwkont:correspondence:time:005	GFO	Time (+ Space_time, Temporal_region, Chronoid, Time_boundary)	https://w3id.org/gfo/base/Time, /Space_time, /Temporal_region, /Chronoid, /Time_boundary	GFO 2024-11-18 (directly verified 2026-07-04)	xwkont:ref:gfo	Direct terminological match; the only source with an explicitly named philosophical lineage (Brentano, Allen & Hayes) for its Time treatment.
xwkont:correspondence:time:006	TUpper	Timepoint	not applicable — TUpper/PSL term names are their own identifiers, no opaque ID scheme	COLORE formalization, undated (directly verified 2026-07-04)	xwkont:ref:tupper-colore	Included as TUpper's only temporal class, despite covering only the instant case (no interval/duration counterpart).
xwkont:correspondence:time:007	GUM	Time (+ TemporalObject, TimeInterval, TimePoint, 14 further subtypes)	http://www.ontospace.uni-bremen.de/ontology/stable/GUM-3.owl#Time (+ sibling IRIs in the same namespace)	GUM 3.1 (directly verified 2026-07-04)	xwkont:ref:gum-owl	The richest temporal apparatus of any of the 8 sources; included despite its linguistic (not metaphysical) grounding criterion.

No YAMATO correspondence is recorded — see Source Definitions and Uncertainty; no Time-related class was found in the one YAMATO document that is fetchable, and this is recorded as a scoped absence, not a settled claim about YAMATO overall.

Semantic Comparison Notes

Note ID	Dimension	Claim type	Note	Supporting references	Confidence
note-001	philosophical	editorial observation	BFO alone classifies Time as a subtype of Occurrent. Every other source with a Time category (DOLCE, SUMO, GFO, TUpper, GUM) treats it as independent of the occurrent/continuant-equivalent split entirely: DOLCE files it as an abstract quality-space region; SUMO files it under Abstract/Quantity, disjoint from Physical (where Process sits); GFO gives it its own sui generis branch, explicitly disjoint from both Presential and Occurrent; TUpper makes it one of four flat top-level classes; GUM's Time has a dual parent (Substance/TemporalObject) ancestor to neither its occurrent-like nor continuant-like classes. This is the sharpest structural divergence found in this crosswalk — a genuine disagreement about where Time belongs in each source's top-level architecture, not a labeling difference.	xwkont:ref:bfo-2020, xwkont:ref:dolce-lite-owl, xwkont:ref:sumo-niles-pease-2001, xwkont:ref:gfo, xwkont:ref:tupper-colore, xwkont:ref:gum-owl	high
note-002	philosophical	direct quotation	GFO's Time class definition names an explicit philosophical/formal lineage — "The time model of GFO is based on Brentano and the glass continuum of Allen&Hayes" — the only source among all 8 to embed a named theoretical grounding directly inside its Time class definition, rather than in a separate paper or left ungrounded.	xwkont:ref:gfo	high
note-003	technical	editorial observation	GUM's temporal apparatus (18 classes) is explicitly grounded in Halliday & Matthiessen's (1999) systemic-functional-linguistics theory of the clause — cited by page number directly inside multiple class definitions — modeling grammatical tense/aspect/boundedness realization, not time as a mind-independent feature of reality. This is the same linguistic-vs-metaphysical grounding pattern already found for GUM's Process (process.md) and Quality (quality.md), extended here to Time.	xwkont:ref:gum-owl	high
note-004	technical	editorial observation	SUMO's TimeMeasure sits on the Abstract side of its Physical/Abstract split, the same side as Attribute (quality.md) and Relation/Proposition — while SUMO's Process (its occurrent-like category) sits on the Physical side. This means SUMO's Time and Process categories are further apart in SUMO's own top-level architecture than any other source's equivalent pairing — a distinctive, not merely incidental, structural fact about SUMO's Time treatment.	xwkont:ref:sumo-niles-pease-2001	high
note-005	technical	editorial observation	This crosswalk's own research corrected docs/evaluations/foundational-ontology-concept-terms-matrix.md's "Observation 2," which had claimed only 5 sources have an explicit Time category (omitting SUMO's TimeMeasure/TimeInterval/TimePoint, missed by that document's shallower pass, and omitting GUM's Time treatment entirely, apparently never checked). The matrix has been corrected as part of this session's work — see that document's own updated observation and the underlying ref-sumo-niles-pease-2001.md/ref-gum-owl.md verification notes.	xwkont:ref:sumo-niles-pease-2001, xwkont:ref:gum-owl	high

Mapping Assertions or Candidate Relations

Mapping ID	Subject	Relation category	Object	predicate_id	mapping_justification	Status	Confidence	Rationale	Provenance
xwkont:mapping:time:001	BFO:Temporal region	overlap	DOLCE:Temporal-region	none	semapv:ManualMappingCuration	candidate	high	Same subject matter (temporal extent) but a genuine top-level classification divergence: BFO subsumes it under Occurrent; DOLCE files it as an abstract quality-space region, neither endurant nor perdurant. Not close-match because the classification difference is structural, not incidental.	xwkont:ref:bfo-2020, xwkont:ref:dolce-lite-owl
xwkont:mapping:time:002	BFO:Temporal region	overlap	SUMO:TimeMeasure	none	semapv:ManualMappingCuration	candidate	high	Same divergence pattern as mapping-001: BFO=occurrent, SUMO=abstract quantity, disjoint from SUMO's own occurrent-like Physical/Process side.	xwkont:ref:bfo-2020, xwkont:ref:sumo-niles-pease-2001
xwkont:mapping:time:003	BFO:Temporal region	overlap	GFO:Space_time	none	semapv:ManualMappingCuration	candidate	high	Same divergence pattern: BFO=occurrent; GFO explicitly declares its Time branch sui generis and disjoint from both Presential and Occurrent.	xwkont:ref:bfo-2020, xwkont:ref:gfo
xwkont:mapping:time:004	BFO:Temporal instant	close-match	TUpper:Timepoint	skos:closeMatch	semapv:ManualMappingCuration	candidate	medium-high	Both denote an instant-like, extensionless point in a linear temporal order. Not high because TUpper's timepoint is its only temporal class (no interval/duration counterpart), a narrower overall scope than BFO's full temporal-region hierarchy — a sourcing/scope-driven gap, not a substantive disagreement about what an instant is.	xwkont:ref:bfo-2020, xwkont:ref:tupper-colore
xwkont:mapping:time:005	BFO:Temporal region	overlap	GUM:Time	none	semapv:ManualMappingCuration	candidate	medium	Same classification-divergence pattern as mapping-001–003, compounded by GUM's linguistic (not metaphysical) grounding criterion — the weakest structural alignment of the Occurrent-vs-independent-category comparisons, hence medium not high.	xwkont:ref:bfo-2020, xwkont:ref:gum-owl
xwkont:mapping:time:006	DOLCE:Temporal-region	overlap	SUMO:TimeMeasure	none	semapv:ManualMappingCuration	candidate	medium	Downgraded from close-match (2026-07-04 review pass) — both classify Time as independent of their occurrent-equivalent category (DOLCE: region; SUMO: abstract quantity), closer to each other than either is to BFO's occurrent classification, but "region" and "abstract quantity" are different formal kinds, not merely differing scope/axioms within the same kind (contrast mapping-007, where both sides are region-denoting categories). close-match per docs/methodology/crosswalk-methodology.md is for concepts "similar enough to align for many purposes but differ in scope, axioms, usage, or context" — a difference in formal kind is a stronger divergence than that, so overlap ("partially intersect but neither subsumes the other") is the better fit.	xwkont:ref:dolce-lite-owl, xwkont:ref:sumo-niles-pease-2001
xwkont:mapping:time:007	DOLCE:Temporal-region	close-match	GFO:Temporal_region	skos:closeMatch	semapv:ManualMappingCuration	candidate	high	Both are non-occurrent, region-denoting categories with near-identical naming (temporal-region/Temporal_region) and near-identical gloss (region/mereological-sum-of-time framing). The closest structural pairing found in this crosswalk.	xwkont:ref:dolce-lite-owl, xwkont:ref:gfo
xwkont:mapping:time:008	GFO:Temporal_region	overlap	GUM:TemporalObject	none	semapv:ManualMappingCuration	candidate	high	Downgraded from close-match (2026-07-04 review pass) — both are independent, sui-generis-flavored top-level categories not subsumed under either occurrent-like or continuant-like classes, but GFO's grounding is metaphysical (Brentano/Allen & Hayes) while GUM's is linguistic (Halliday & Matthiessen) — a difference in the kind of independence claimed, not just scope or axioms within a shared formal kind. overlap ("partially intersect but neither subsumes the other," per docs/methodology/crosswalk-methodology.md) better reflects that than close-match. high confidence in the overlap category: the grounding difference is directly stated in each source's own text, not an open sourcing question.	xwkont:ref:gfo, xwkont:ref:gum-owl
xwkont:mapping:time:009	SUMO:TimeMeasure	related	GUM:Time	skos:relatedMatch	semapv:ManualMappingCuration	candidate	high	Both treat time as a measured/graded quantity-like thing rather than an occurrent, but SUMO's framing is a universal-timeline quantity while GUM's is a clause-level aspectual category — related in spirit, not close enough in formal apparatus for close-match. high confidence in the related category: this formal-apparatus divergence is directly evidenced by each source's own text, not an open sourcing question.	xwkont:ref:sumo-niles-pease-2001, xwkont:ref:gum-owl
xwkont:mapping:time:010	xwkont-core:Time (candidate)	unknown	UFO	none	semapv:ManualMappingCuration	candidate	low	No UFO correspondence identified; UFO's only temporal content is Perdurant's own "unfold in time" property, not a reified Time class. Recorded explicitly rather than silently omitted, per this repository's established practice for negative findings (e.g. quality.md's TUpper mapping).	xwkont:ref:ufo-2021
xwkont:mapping:time:011	xwkont-core:Time (candidate)	unknown	YAMATO	none	semapv:ManualMappingCuration	candidate	low	No YAMATO correspondence identified in the one fetchable YAMATO document; scoped absence, not a settled claim (OWL/Hozo files remain registration-gated, 2022 paper remains blocked).	xwkont:ref:yamato-mizoguchi-2010

Uncertainty, Non-Equivalence, and Open Questions

Item ID	Type	Description	Impact	Follow-up
uncertainty-001	open-question	Where should xwkont-core:Time subclass from once added to data/ontology/core.ttl? note-001's finding (all 5 non-BFO sources with a Time category classify it as independent of the occurrent/continuant split) is real evidence against simply subclassing xwkont-core:Occurrent the way BFO does, but XwkOnt's own core split (Continuant/Occurrent under Entity, per data/ontology/core.ttl) has no independent third branch today — Relation and InformationArtifact are the only precedents for a direct-Entity subclass bypassing Continuant/Occurrent.	Blocks final core.ttl placement; does not block continuing this crosswalk's research/review.	Decide at review time, informed by this crosswalk's cross-source evidence and by whatever placement Space/Region (a related 0.2.0-batch candidate) ends up using, since several sources treat Time and Space as siblings.
uncertainty-002	non-equivalence	UFO has no reified Time/TemporalRegion/Instant/Interval class in either the 2021 paper or the OntoUML vocabulary fallback — confirmed by direct full-text search of both, not inferred from silence in a summary.	No UFO correspondence recorded (correspondence-004, mapping-010).	Re-check if UFO-A/UFO-C literature (already flagged as unfetched in TODO.md for information-artifact.md) becomes accessible — it might elaborate a temporal category the 2021 comprehensive paper omits.
uncertainty-003	open-question	YAMATO's absence of a Time category is confirmed only against the one fetchable primary document (the 2010 technical report); its OWL/Hozo files remain behind the hozo.jp registration gate and the 2022 Applied Ontology paper remains blocked by the same Cloudflare pattern affecting other sources' 2022 papers.	This crosswalk records "not found in the fetchable material," not "YAMATO has no Time category" — a scoped, not settled, absence.	Re-check if either the OWL/Hozo files (registration completed) or the 2022 paper (access resolved) become available in a future pass.
uncertainty-004	open-question	This crosswalk does not address Spatial Region/Space, though several sources (BFO's spatiotemporal region, GFO's Space_time) structurally pair Time with Space as siblings under a shared parent — a relationship worth revisiting once Space is itself scoped.	Scopes this crosswalk to Time only, consistent with ADR-0018's one-concept-per-pass process.	~~Create the Spatial Region/Space concept crosswalk next~~ — done (space.md reviewed). Residual cross-check whether Time/Space's sibling relationship in several sources should be reflected in XwkOnt's own core.ttl structure remains open.
uncertainty-005	open-question	GUM's Time class has a dual parent (Substance and TemporalObject) — Substance did not appear in the 3-level-deep tree previously captured for GUM in docs/evaluations/foundational-ontology-concept-terms-matrix.md, suggesting that tree may be missing other classes beyond its stated scope, similar to the SUMO gap this session corrected.	Does not affect this crosswalk's own GUM correspondence (Time's definition and both parents are directly quoted from the primary source), but flags a possible completeness gap in the matrix beyond Time specifically.	A future pass revisiting the matrix's GUM tree could check for a Substance branch and what else might sit under it.
uncertainty-006	non-equivalence	Correction, found via space.md's research (2026-07-04): the Source Definitions row above claims "Neither Process... nor SimpleThing... is an ancestor of any GUM temporal class." This is incorrect as to SimpleThing: the transitive chain TemporalObject → SpatialTemporal → NonConsciousThing → SimpleThing is directly confirmed in GUM-31.owl. The direct-parent finding (Time's own rdfs:subClassOf is Substance/TemporalObject, not Process/SimpleThing) still stands and is what note-001's classification argument actually rests on — only the stronger "no ancestor at all" phrasing was wrong.	Does not change this crosswalk's central classification finding (note-001), since that argument is about direct parentage, not deep transitive ancestry.	None outstanding — recorded here for traceability; the Source Definitions row itself now carries an inline correction note.

Provenance and References

• xwkont:ref:bfo-2020 — Basic Formal Ontology (BFO) 2020 / ISO/IEC 21838-2:2021 — verified directly against bfo-core.ttl, 2026-07-04
• xwkont:ref:dolce-lite-owl — DOLCE-Lite OWL translation — verified directly against DOLCE-Lite.owl, 2026-07-04
• xwkont:ref:sumo-niles-pease-2001 — Towards a Standard Upper Ontology (Niles & Pease, 2001) — verified directly against current SUMO Merge.kif, 2026-07-04, correcting the matrix's prior undercount
• xwkont:ref:ufo-2021 — UFO: Unified Foundational Ontology (Guizzardi et al., 2021) — verified absence directly, 2026-07-04
• xwkont:ref:ontouml-vocabulary — OntoUML Vocabulary (OWL/Turtle) — verified absence directly (fallback check), 2026-07-04
• xwkont:ref:gfo — General Formal Ontology (GFO) — verified directly against modules/gfo-base.owl, 2026-07-04
• xwkont:ref:yamato-mizoguchi-2010 — YAMATO 2010 technical report (Mizoguchi) — verified absence, scoped directly against the extracted PDF, 2026-07-04
• xwkont:ref:tupper-colore — TUpper COLORE formalization (Grüninger) — verified directly against TUpper-Terms.html, 2026-07-04
• xwkont:ref:gum-owl — GUM 3.1 OWL (Bateman) — verified directly against GUM-31.owl, 2026-07-04, correcting the matrix's prior omission

Review History

Review ID	Date	Outcome	Notes
—	2026-07-04	Not yet reviewed — draft	First pass of the 0.2.0 batch (ADR-0018). All 8 sources checked directly against primary artifacts in a single research pass (delegated to a research agent, then written up directly), rather than the phased BFO/DOLCE/UFO/SUMO-then-ADR-0015-buildout pattern the original 8 concepts followed — a single-pass process is possible here because all 8 sources' reference records and fetch paths already existed from that earlier buildout. Corrected two errors in docs/evaluations/foundational-ontology-concept-terms-matrix.md (SUMO and GUM's Time content, both previously missed or omitted) as a side effect of this research. Pending maintainer review before advancing to reviewed; core.ttl placement (uncertainty-001) is an open question to resolve at that review, not before.
xwkont:review:time:2026-07-05:01	2026-07-05	Passed — advanced draft → reviewed	Checked against docs/governance/contributing.md's Review Checklist: scope preserved; every xwkont:ref:* citation resolves; correspondence/mapping/note/uncertainty ID numbering sequential (correspondences 001-007, mappings 001-011, notes 001-005, uncertainty 001-006); all confidence values within the ADR-0013 vocabulary. Correction (2026-07-06, full-corpus audit): this entry originally claimed "both medium-high/low-medium mappings (004, 008, 009) state a sourcing-driven rationale" — true for 004 (TUpper's narrower scope, a genuine coverage gap), false for 008/009, whose rationales explicitly describe substantive/kind-level differences (metaphysical vs. linguistic grounding; universal-timeline quantity vs. clause-level aspect), not sourcing changes. Both raised to high confidence in this pass, keeping their already-correct overlap/related categories — the divergence itself is clearly evidenced, not an open sourcing question. See docs/methodology/crosswalk-runbook.md's governing principle. The 2026-07-04 external review's downgrade of mapping-006/mapping-008 from close-match to overlap confirmed correctly applied. uncertainty-001 (core.ttl placement — whether Time gets an independent third branch alongside Continuant/Occurrent) is not resolved by this review and is explicitly deferred as separate data/ontology/core.ttl (Turtle-change) work, per docs/INFORMATION_ARCHITECTURE.md's definition of reviewed as passing review "for its stated scope" (the cross-source comparison), not requiring core.ttl placement to be simultaneously settled — same precedent as proposition-content.md's and situation-state-of-affairs.md's deferred-placement advances. Self-review, not independent third-party review.

Future Work

• ~~Resolve uncertainty-001~~ — done 2026-07-05: advanced draft → reviewed (xwkont:review:time:2026-07-05:01); core.ttl placement remains a separately-tracked open question, to be decided jointly with space.md's uncertainty-002 (see that crosswalk).
• ~~Create the Spatial Region/Space crosswalk next~~ — done (space.md reviewed). Residual check whether Time/Space's sibling relationship in several sources (uncertainty-004) should inform either crosswalk's final core.ttl placement.
• Re-check UFO (uncertainty-002) and YAMATO (uncertainty-003) if their currently-blocked/gated primary sources become accessible.
• Check whether GUM's Substance branch (uncertainty-005) reveals other classes missing from the matrix's GUM tree, beyond Time.
• mapping-006 and mapping-008 downgraded from close-match to overlap in a 2026-07-04 external review pass — both paired categories of different formal kind (region/quantity; metaphysical/linguistic grounding), which close-match understates per docs/methodology/crosswalk-methodology.md's own distinction from overlap.