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Continuant / Occurrent

Local identifier: xwkont:concept:continuant-occurrent Slug: continuant-occurrent Editorial status: reviewed Created: 2026-07-01 Modified: 2026-07-06

Scope Note

This crosswalk compares the top-level temporal-persistence split found in BFO (continuant/occurrent), DOLCE (endurant/perdurant), and UFO (endurant/perdurant), and a structurally different but often-compared analog in SUMO (Object/Process under a Physical/Abstract partition). It is XwkOnt's first concept crosswalk, chosen deliberately over a more concrete concept (e.g., Object) because it is the most abstract split each source ontology makes, is the best-evidenced in existing comparative literature, and directly validates XwkOnt's own top-level scaffold (xwkont-core:Continuant, xwkont-core:Occurrent in data/ontology/core.ttl) against real source definitions.

Exclusions: this crosswalk does not resolve the Process/Event distinction within Occurrent (a separate, already-flagged open question — see Uncertainty).

Update (2026-07-02), GFO/YAMATO/TUpper/GUM buildout: ADR-0015 (2026-07-02) expanded XwkOnt's source-ontology scope to include GFO, YAMATO, TUpper, and GUM. This crosswalk is the first to receive the resulting content buildout, resolving uncertainty-004. None of the four use "continuant/occurrent" terminology identically to BFO/DOLCE/UFO:

  • GFO uses its own top-level pair, Presential/Occurrent (not "Continuant") — Occurrent is shared vocabulary with BFO/DOLCE/UFO's occurrent side, but the continuant-side term differs.
  • YAMATO uses Continuant/Occurrent directly, parenthetically glossed as Object/Process, with an explicit refusal to use "perdurant."
  • TUpper uses no continuant/occurrent-style label at all — its PSL-derived vocabulary (object/activity_occurrence) defines object negatively (anything that is not a timepoint, activity, or activity-occurrence).
  • GUM uses no continuant/occurrent-style label either — its SimpleThing/Process split is grounded in systemic-functional linguistics (participant vs. verb-realized "goings-on"), not a metaphysical persistence criterion, structurally closer to this crosswalk's existing SUMO precedent than to BFO/DOLCE/UFO.

Each source's OWL/CLIF files were fetched and read directly (no PDF extraction needed for GFO or TUpper/GUM's OWL; a 2010 YAMATO technical report PDF was extracted for YAMATO since its dedicated 2022 paper and OWL/Hozo download were both inaccessible — see note-004 and the relevant reference records for details).

Update (2026-07-01), following direct primary-source verification of DOLCE and UFO: the WonderWeb D18 report and the UFO 2021 Applied Ontology paper (already fetched and extracted for other crosswalks — object.md, role.md, process.md, relation.md) were reused to verify this crosswalk's DOLCE and UFO content directly, resolving uncertainty-001. Findings:

  • DOLCE's endurant/perdurant definitions are confirmed, with more exact wording than the earlier secondary-source paraphrase: "Endurants are wholly present (i.e., all their proper parts are present) at any time they are present. Perdurants, on the other hand, just extend in time by accumulating different temporal parts, so that, at any time they are present, they are only partially present." D18 also directly confirms note-002's claim about DOLCE's cognitive orientation, in the authors' own words: "we must emphasise that this distinction is motivated by our cognitive bias, and we do not commit to the fact that both these kinds of entity really exist."
  • UFO's endurant/perdurant definitions are confirmed as originally paraphrased, now as a direct quotation: "UFO distinguishes between endurants and perdurants. Endurants are individuals that exist in time with all their parts. Perdurants are individuals that unfold in time accumulating temporal parts. An endurant can change while maintaining its identity, a perdurant cannot."
  • uncertainty-001 (UFO's philosophical grounding) is resolved. The 2021 paper traces UFO's origin to conceptual-modeling ontology evaluation work (Bunge-Wand-Weber), later merging with DOLCE and the General Formal Ontology (GFO) on the basis of a shared commitment to a four-category ontology ("the Aristotelian Square," per Lowe 2006) distinguishing individuals/types crossed with substantials/moments. This is a different philosophical lineage from both BFO's realist/scientific-practice grounding and DOLCE's cognitive/linguistic orientation — UFO's stated motivation is explicitly the practical requirements of conceptual modeling languages, informed by analytic four-category ontology, not a cognitive-bias disclaimer or a scientific-realist stance.

Epistemic note: BFO and SUMO content is verified directly against primary sources (bfo-core.ttl, Merge.kif). DOLCE and UFO content is now also directly verified (2026-07-01), reusing extractions performed for other crosswalks in this repository. The xwkont:ref:borgo-galton-kutz-2022 editorial framing (BFO's "realist" and DOLCE's "cognitive/linguistic" characterizations) remains secondary-sourced and unverified — see Future Work.

Labels, Alternate Labels, and Source Terminology

Role Label or term Source Language Notes
XwkOnt working label Continuant / Occurrent XwkOnt en Matches xwkont-core:Continuant/xwkont-core:Occurrent in data/ontology/core.ttl.
Source term continuant / occurrent BFO en
Source term endurant / perdurant DOLCE en
Source term endurant / perdurant (event) UFO en UFO uses "event" for a kind of perdurant; see Source Definitions.
Alternate label Object / Process (under Physical) SUMO en Not labeled "continuant/occurrent" by SUMO itself; included as a structural analog only — see Uncertainty.
Source term Presential / Occurrent GFO en GFO's own top-level pair; "Continuant" is not GFO's term (see Uncertainty).
Source term Continuant(Object) / Occurrent(Process) YAMATO en YAMATO uses "Continuant"/"Occurrent" directly, glossing them parenthetically as Object/Process.
Alternate label object / activity_occurrence TUpper en Not labeled "continuant/occurrent" by TUpper; PSL-derived vocabulary, object defined negatively — see Uncertainty.
Alternate label SimpleThing / Process GUM en Not labeled "continuant/occurrent" by GUM; a linguistic (participant vs. verb-realized "goings-on") split, not a metaphysical one — see Uncertainty.

Source Definitions and Contextual Notes

Source Term or identifier Dimension Claim type Definition, quotation, or paraphrase Reference Locator Notes
BFO continuant (BFO_0000002) technical direct quotation "(Elucidation) A continuant is an entity that persists, endures, or continues to exist through time while maintaining its identity." Examples: "A human being; a tennis ball; a cave; a region of space; someone's temperature." xwkont:ref:bfo-2020 verified: bfo-core.ttl, class BFO_0000002, fetched and read directly 2026-07-01 Confirms the earlier secondary-source paraphrase closely.
BFO occurrent (BFO_0000003) technical direct quotation "(Elucidation) An occurrent is an entity that unfolds itself in time or it is the start or end of such an entity or it is a temporal or spatiotemporal region." Examples given: "process, history, process boundary, spatiotemporal region, zero-dimensional temporal region, one-dimensional temporal region, temporal interval, temporal instant." xwkont:ref:bfo-2020 verified: bfo-core.ttl, class BFO_0000003, fetched and read directly 2026-07-01 Confirms the earlier paraphrase and additionally reveals a fuller definition (occurrent also covers temporal/spatiotemporal regions, not just "dynamic processes").
BFO continuant/occurrent split philosophical paraphrase BFO's continuant/occurrent split reflects a realist framework grounded in scientific practice. xwkont:ref:borgo-galton-kutz-2022 editorial framing from the special-issue editorial, not BFO's own text This is a secondary characterization, not BFO's self-description.
DOLCE endurant technical direct quotation "Endurants are wholly present (i.e., all their proper parts are present) at any time they are present." xwkont:ref:dolce-wonderweb-d18 verified: WonderWeb D18 PDF, manually extracted 2026-07-01 Corrects the earlier secondary-source wording ("necessarily wholly present in each time interval at which they exist") to the primary text's exact phrasing — same meaning, now exact.
DOLCE perdurant technical direct quotation "Perdurants, on the other hand, just extend in time by accumulating different temporal parts, so that, at any time they are present, they are only partially present." xwkont:ref:dolce-wonderweb-d18 verified: WonderWeb D18 PDF, manually extracted 2026-07-01 Same correction as the endurant row above.
DOLCE endurant/perdurant split philosophical direct quotation "[W]e must emphasise that this distinction is motivated by our cognitive bias, and we do not commit to the fact that both these kinds of entity really exist." xwkont:ref:dolce-wonderweb-d18 verified: WonderWeb D18 PDF, manually extracted 2026-07-01 This is now DOLCE's own text, directly confirming (not just via editorial paraphrase from xwkont:ref:borgo-galton-kutz-2022) the "cognitive bias" framing in note-002.
UFO endurant technical direct quotation "Endurants are individuals that exist in time with all their parts." xwkont:ref:ufo-2021 verified: Applied Ontology 2021 PDF, manually extracted 2026-07-01 Confirms the earlier paraphrase exactly; now a direct quotation.
UFO perdurant / event technical direct quotation "Perdurants are individuals that unfold in time accumulating temporal parts. An endurant can change while maintaining its identity, a perdurant cannot." xwkont:ref:ufo-2021 verified: Applied Ontology 2021 PDF, manually extracted 2026-07-01 UFO's theory of events additionally covers mereology, temporal ordering, participation, causation, and change — see event.md, not elaborated here.
UFO endurant/perdurant split (philosophical grounding) philosophical paraphrase UFO's project began from evaluating conceptual-modeling languages against the Bunge-Wand-Weber (BWW) ontology, then merged DOLCE with the General Formal Ontology (GFO) on the shared basis of a four-category ontology ("the Aristotelian Square," per Lowe 2006) crossing individuals/types with substantials/moments. xwkont:ref:ufo-2021 verified: Applied Ontology 2021 PDF, manually extracted 2026-07-01 Resolves uncertainty-001. A different lineage from BFO's realist/scientific-practice grounding and DOLCE's cognitive-bias disclaimer: UFO's stated motivation is conceptual-modeling practice, informed by analytic four-category ontology.
SUMO Physical technical direct quotation "(subclass Physical Entity)... An entity that has a location in space-time. Note that locations are themselves understood to have a location in space-time." Object and Process are both (subclass ... Physical). xwkont:ref:sumo-niles-pease-2001 verified: Merge.kif, documentation Physical EnglishLanguage, fetched and read directly 2026-07-01 The source contains a commented-out (inactive) (partition Physical Object Process) line — Object/Process are each independently asserted as subclasses of Physical, but their joint-exhaustiveness as a formal partition is not an active axiom in current SUMO, only an apparent intention.
SUMO Object technical paraphrase Object is a subclass of Physical, one branch of SUMO's top-level EntityPhysical/Abstract partition. Confirmed directly (see object.md's verified quote: "Corresponds roughly to the class of ordinary objects"). xwkont:ref:sumo-niles-pease-2001 verified (see object.md for the full quotation) Not labeled "continuant" by SUMO.
SUMO Process technical paraphrase Process is a subclass of Physical, the sibling branch to Object. Confirmed directly (see process.md's verified quote: "anything that occurs in time but is not an Object"). xwkont:ref:sumo-niles-pease-2001 verified (see process.md for the full quotation) SUMO's partition criterion is physicality, not temporal persistence — see Uncertainty.
SUMO Object/Process split philosophical editorial observation SUMO is organized for interoperability among automated reasoning engines, an engineering-first purpose rather than an explicit metaphysical grounding of the kind BFO/DOLCE/UFO state. xwkont:ref:sumo-niles-pease-2001 paraphrase of the source's own stated purpose This is an observation about stated purpose, not a claim that SUMO lacks any philosophical basis.
GFO Occurrent technical direct quotation "Occurrents have temporal parts and thus cannot be present at a time-boundary. Time belongs to them, because they happen in time and the time of the occurrent is built into it. The relation between an occurrent and a chronoid is determined by the projection relation. Occurrents are also called generalized processes in the GFO." xwkont:ref:gfo verified: modules/gfo-base.owl, class Occurrent, fetched and read directly 2026-07-02 owl:disjointWith Presential. Shares the term "occurrent" with BFO/DOLCE/UFO's occurrent side.
GFO Presential technical direct quotation "A presential exists wholly at exactly one time boundary." xwkont:ref:gfo verified: modules/gfo-base.owl, class Presential, fetched and read directly 2026-07-02 GFO's continuant-side term is "Presential," not "Continuant" — GFO does not use "continuant" anywhere in the base module.
GFO Process technical direct quotation "Processes are a special kind of occurrent. Processes are directly in time, they have characteristics which cannot be captured by a collection of time boundaries." xwkont:ref:gfo verified: modules/gfo-base.owl, class Process, fetched and read directly 2026-07-02 Subclass of Occurrent, included for comparison with the other sources' Process/Occurrent nesting.
GFO Presential/Occurrent split philosophical editorial observation GFO is explicitly 4D-oriented (per YAMATO's own comparative framing, xwkont:ref:yamato-mizoguchi-2010: "GFO is based on 4D view"), unlike DOLCE's stated 3D orientation. GFO's own OWL files carry no explicit philosophical-grounding prose comparable to DOLCE's "cognitive bias" disclaimer or UFO's four-category-ontology lineage. xwkont:ref:gfo, xwkont:ref:yamato-mizoguchi-2010 secondary characterization (YAMATO's framing of GFO), not GFO's own text Included with lower confidence than the BFO/DOLCE/UFO philosophical rows, which are either primary-sourced or (for BFO) explicitly flagged unverified.
YAMATO Continuant(Object) technical direct quotation "(4) Continuant(Object) vs. Occurrent(Process) ... Common sense is based on 3D model which consists of the 3D Euclidean space with absolute time. YAMATO is based on a solid theory of objects, processes and events, and it deals with them of equal importance (Galton 2009)." xwkont:ref:yamato-mizoguchi-2010 verified: 2010 technical report PDF, manually extracted 2026-07-02 YAMATO uses "Continuant" directly as a top-level label, parenthetically glossed as "Object."
YAMATO Occurrent(Process) technical direct quotation "Furthermore, it clearly identifies events are made of processes and while processes can change, events cannot. We do not use the term perdurant for explaining processes because it blocks to talk about the difference between processes and events." xwkont:ref:yamato-mizoguchi-2010 verified: 2010 technical report PDF, manually extracted 2026-07-02 YAMATO explicitly declines DOLCE/UFO's "perdurant" terminology for this reason.
YAMATO Continuant/Occurrent split philosophical direct quotation "The standpoint taken in YAMATO consists of Newtonian world point of view and 3D-like modeling, that is, the world is considered as being composed of the three-dimensional Euclidean space with the absolute time and both object(continuant) and process (occurrent) exist with equal importance in a mutually-dependent manner." xwkont:ref:yamato-mizoguchi-2010 verified: 2010 technical report PDF, manually extracted 2026-07-02 Distinct from BFO/DOLCE/UFO: YAMATO explicitly treats continuant and occurrent as mutually dependent, rejecting the idea that either is ontologically prior to the other.
TUpper object technical direct quotation "An object is anything that is not a timepoint, nor an activity nor an activity-occurrence. Intuitively, an object is a concrete or abstract thing that can participate in an activity. Objects can come into existence (be created) and go out of existence (be 'used up' as a resource) at certain points in time." xwkont:ref:tupper-colore verified: TUpper-Terms.html, term object, fetched and read directly 2026-07-02 Defined negatively (by exclusion), not by a positive temporal-persistence criterion — a different definitional style from every other source in this crosswalk.
TUpper activity_occurrence technical direct quotation "An activity occurrence is associated with a unique activity" via the occurrence_of relation; "occ is a member of the class of activity occurrences in the universe of discourse of the interpretation." xwkont:ref:tupper-colore verified: TUpper-Terms.html, term activity_occurrence, fetched and read directly 2026-07-02 TUpper's closest analog to "occurrent" — an occurrence tied to a specific activity, inherited from PSL.
TUpper object/activity_occurrence split philosophical editorial observation TUpper's vocabulary is inherited from PSL (Process Specification Language), an engineering/manufacturing-process ontology, not a philosophical top-level ontology in the BFO/DOLCE/UFO sense — closer in spirit to SUMO's engineering-first framing (note-003) than to the three metaphysically-grounded sources. xwkont:ref:tupper-colore paraphrase, based on PSL's documented purpose and TUpper's own negative-definition style Not a claim that TUpper lacks any theoretical grounding — ISO/IEC 21838-4:2023's own text (not accessed in this pass) may state one explicitly.
GUM SimpleThing technical direct quotation "An entity which may participate in a configuration." xwkont:ref:gum-owl verified: GUM-31.owl, class SimpleThing, fetched and read directly 2026-07-02 Subclass of Element; GUM's closest analog to "continuant" — a participant, not a temporally-persisting substance per se.
GUM Process technical direct quotation "A Process is the linguistic construal of 'goings-on' or events. Processes are similar to Configurations, but factor out Participants, Circumstances, and other elements. As such, entities classified under Process can be expressed as verbs and are frequently the main verb in a clause." xwkont:ref:gum-owl verified: GUM-31.owl, class Process, fetched and read directly 2026-07-02 owl:disjointWith SimpleThing; a linguistic (verb-realized) criterion, not temporal persistence.
GUM SimpleThing/Process split philosophical editorial observation GUM's split is grounded in systemic-functional linguistics (Halliday & Matthiessen's transitivity model — participants vs. processes as clause elements), explicitly stated in GUM's own class comments, not in a metaphysical persistence criterion. xwkont:ref:gum-owl direct quotation basis, editorial synthesis of the pattern across GUM's class comments Structurally the closest precedent in this crosswalk is SUMO's engineering-first framing (note-003), though GUM's motivation (linguistic mediation) differs from SUMO's (reasoner interoperability).

Source Ontology Correspondences

Correspondence ID Source ontology Source term Source identifier or IRI Source version Reference Inclusion rationale
xwkont:correspondence:continuant-occurrent:001 BFO continuant BFO_0000002 BFO 2020 xwkont:ref:bfo-2020 XwkOnt's own scaffold (xwkont-core:Continuant) is most directly modeled on BFO's split.
xwkont:correspondence:continuant-occurrent:002 BFO occurrent BFO_0000003 BFO 2020 xwkont:ref:bfo-2020 Same as above, for xwkont-core:Occurrent.
xwkont:correspondence:continuant-occurrent:003 DOLCE endurant http://www.loa-cnr.it/ontologies/DOLCE-Lite.owl#endurant (confirmed directly, 2026-07-01) WonderWeb D18, 2003 (directly verified 2026-07-01) xwkont:ref:dolce-wonderweb-d18, xwkont:ref:dolce-lite-owl Widely cited alternate top-level pair using the same temporal-persistence criterion as BFO.
xwkont:correspondence:continuant-occurrent:004 DOLCE perdurant http://www.loa-cnr.it/ontologies/DOLCE-Lite.owl#perdurant (confirmed directly, 2026-07-01) WonderWeb D18, 2003 (directly verified 2026-07-01) xwkont:ref:dolce-wonderweb-d18, xwkont:ref:dolce-lite-owl Same as above.
xwkont:correspondence:continuant-occurrent:005 UFO endurant not applicable — UFO's 2021 paper is natural-language prose with no IRI scheme of its own; gUFO (a derived OWL implementation) has IRIs but is not treated as identical to UFO's own theoretical claims, per xwkont:ref:ufo-2021's Source Relation Notes Applied Ontology, 2021 (directly verified 2026-07-01) xwkont:ref:ufo-2021 UFO explicitly continues DOLCE's endurant/perdurant lineage.
xwkont:correspondence:continuant-occurrent:006 UFO perdurant / event not applicable — same as row 005 Applied Ontology, 2021 (directly verified 2026-07-01) xwkont:ref:ufo-2021 Same as above.
xwkont:correspondence:continuant-occurrent:007 SUMO Object Object (SUMO/SUO-KIF has no separate opaque identifier scheme — the term name itself, as it appears in Merge.kif, is the identifier) 2001 (Niles & Pease) xwkont:ref:sumo-niles-pease-2001 Included as an exploratory structural analog despite a different top-level partition criterion (physicality, not temporal persistence).
xwkont:correspondence:continuant-occurrent:008 SUMO Process Process (same identifier convention as row 007) 2001 (Niles & Pease) xwkont:ref:sumo-niles-pease-2001 Same as above.
xwkont:correspondence:continuant-occurrent:009 GFO Presential https://w3id.org/gfo/base/Presential GFO 2024-11-18 release (directly verified 2026-07-02) xwkont:ref:gfo GFO's own continuant-side term, structurally parallel to BFO's continuant despite the different label.
xwkont:correspondence:continuant-occurrent:010 GFO Occurrent https://w3id.org/gfo/base/Occurrent GFO 2024-11-18 release (directly verified 2026-07-02) xwkont:ref:gfo Same term label as BFO/DOLCE/UFO's occurrent side.
xwkont:correspondence:continuant-occurrent:011 YAMATO Continuant(Object) not applicable — the 2010 technical report has no OWL IRI scheme; YAMATO's OWL files exist but were not fetched in this pass (registration-gated download, see xwkont:ref:yamato-mizoguchi-2010) 2010 technical report (directly verified 2026-07-02) xwkont:ref:yamato-mizoguchi-2010 YAMATO uses "Continuant" as its own top-level label, the closest terminological match to BFO/XwkOnt of any of the four ADR-0015 sources.
xwkont:correspondence:continuant-occurrent:012 YAMATO Occurrent(Process) not applicable — same as row 011 2010 technical report (directly verified 2026-07-02) xwkont:ref:yamato-mizoguchi-2010 Same as above.
xwkont:correspondence:continuant-occurrent:013 TUpper object object (TUpper/COLORE term name, as it appears in TUpper-Terms.html and the CLIF/OWL files — no opaque identifier scheme, similar in convention to SUMO's Merge.kif terms) COLORE formalization (directly verified 2026-07-02); ISO/IEC 21838-4:2023 standard text not independently accessed xwkont:ref:tupper-colore Included as a structural analog: TUpper's object is defined negatively and inherited from PSL, not a positive temporal-persistence criterion.
xwkont:correspondence:continuant-occurrent:014 TUpper activity_occurrence activity_occurrence (same identifier convention as row 013) COLORE formalization (directly verified 2026-07-02); ISO/IEC 21838-4:2023 standard text not independently accessed xwkont:ref:tupper-colore Same as above.
xwkont:correspondence:continuant-occurrent:015 GUM SimpleThing http://www.ontospace.uni-bremen.de/ontology/stable/GUM-3.owl#SimpleThing GUM 3.1 (directly verified 2026-07-02, via Internet Archive; canonical purl.org/net/gum2 host chain confirmed dead 2026-07-02) xwkont:ref:gum-owl Included as a structural analog only, per the same rationale as SUMO's Object/Process rows (006/007): a different partition criterion (linguistic, not temporal-persistence).
xwkont:correspondence:continuant-occurrent:016 GUM Process http://www.ontospace.uni-bremen.de/ontology/stable/GUM-3.owl#Process GUM 3.1 (directly verified 2026-07-02, via Internet Archive) xwkont:ref:gum-owl Same as above.

Semantic Comparison Notes

Note ID Dimension Claim type Note Supporting references Confidence
note-001 technical editorial observation BFO, DOLCE, and UFO all use the same temporal-persistence criterion for their top-level split: an entity's parts are either all present at once (continuant/endurant) or accumulated/extended through time (occurrent/perdurant), now confirmed directly against all three primary sources. SUMO's Physical/AbstractObject/Process split uses a different criterion (physicality), so structural position in the hierarchy is not identical even where the labels invite comparison. xwkont:ref:bfo-2020, xwkont:ref:dolce-wonderweb-d18, xwkont:ref:ufo-2021, xwkont:ref:sumo-niles-pease-2001 high
note-002 philosophical editorial observation BFO's split is characterized in comparative literature as reflecting a realist framework grounded in scientific practice (unverified, secondary-sourced — see Uncertainty). DOLCE's cognitive/linguistic orientation is now directly confirmed in the primary source's own words: "we must emphasise that this distinction is motivated by our cognitive bias, and we do not commit to the fact that both these kinds of entity really exist." UFO's grounding, previously unconfirmed (uncertainty-001), is now also directly confirmed: a conceptual-modeling origin (evaluating BWW-based approaches) that merged DOLCE and GFO on the basis of a shared four-category-ontology commitment (individuals/types × substantials/moments). Three different philosophical lineages for a formally similar-looking split, two now confirmed by primary-source quotation rather than editorial paraphrase. xwkont:ref:borgo-galton-kutz-2022 (BFO only), xwkont:ref:dolce-wonderweb-d18, xwkont:ref:ufo-2021 high
note-003 technical editorial observation SUMO's Object/Process pair is included as a structural analog only; Niles & Pease (2001) frame SUMO's purpose as interoperability among automated reasoning engines rather than an explicitly philosophically motivated top-level split, in contrast to BFO/DOLCE/UFO's stated theoretical grounding. xwkont:ref:sumo-niles-pease-2001 medium
note-004 technical editorial observation The four ADR-0015 sources use continuant/occurrent-equivalent vocabulary with markedly different terminological fidelity to BFO. YAMATO uses "Continuant"/"Occurrent" directly (the closest match of any source in this crosswalk besides BFO itself). GFO uses "Occurrent" for the same side but "Presential" (not "Continuant") for the other. TUpper and GUM use neither term: TUpper's object/activity_occurrence (PSL-derived, engineering-oriented) and GUM's SimpleThing/Process (linguistically-oriented) are structural analogs only, in the same sense SUMO's Object/Process (note-003) already is — a pattern that now recurs across three of the crosswalk's eight sources rather than being a SUMO-specific exception. xwkont:ref:gfo, xwkont:ref:yamato-mizoguchi-2010, xwkont:ref:tupper-colore, xwkont:ref:gum-owl high (terminology comparison directly verified against each source's own text); confidence on individual cross-source mapping claims is set per-mapping below, not uniformly here

Mapping Assertions or Candidate Relations

Per ADR-0009, each mapping records a predicate_id (SSSOM/SKOS predicate, or none for XwkOnt-only categories) and a mapping_justification (SEMAPV term).

Mapping ID Subject Relation category Object predicate_id mapping_justification Status Confidence Rationale Provenance
xwkont:mapping:continuant-occurrent:001 BFO:continuant close-match DOLCE:endurant skos:closeMatch semapv:ManualMappingCuration candidate high Both defined by the same temporal-persistence criterion (wholly present at each time of existence). Not exact-equivalence-candidate because the two sources' philosophical framing differs (realist vs. cognitive/linguistic per note-002), so full interchangeability across every context is not asserted. xwkont:ref:bfo-2020, xwkont:ref:dolce-wonderweb-d18, xwkont:ref:borgo-galton-kutz-2022
xwkont:mapping:continuant-occurrent:002 BFO:occurrent close-match DOLCE:perdurant skos:closeMatch semapv:ManualMappingCuration candidate high Same rationale as mapping-001, inverse pairing. xwkont:ref:bfo-2020, xwkont:ref:dolce-wonderweb-d18, xwkont:ref:borgo-galton-kutz-2022
xwkont:mapping:continuant-occurrent:003 BFO:continuant close-match UFO:endurant skos:closeMatch semapv:ManualMappingCuration candidate high UFO continues DOLCE's endurant/perdurant lineage using the same temporal-persistence criterion. xwkont:ref:bfo-2020, xwkont:ref:ufo-2021
xwkont:mapping:continuant-occurrent:004 BFO:occurrent close-match UFO:perdurant/event skos:closeMatch semapv:ManualMappingCuration candidate high Same rationale as mapping-003, inverse pairing. xwkont:ref:bfo-2020, xwkont:ref:ufo-2021
xwkont:mapping:continuant-occurrent:005 DOLCE:endurant close-match UFO:endurant skos:closeMatch semapv:ManualMappingCuration candidate high Corrected (2026-07-06, full-corpus audit) from exact-equivalence-candidate (itself raised 2026-07-01 from medium): both primary sources are directly verified and their endurant definitions are near-verbatim ("wholly present... at any time they are present" vs. "individuals that exist in time with all their parts") — UFO's endurant/perdurant split directly continues DOLCE's, confirmed rather than merely asserted. But note-002 documents that DOLCE's split is motivated by an explicit cognitive-bias disclaimer ("we do not commit to the fact that both these kinds of entity really exist"), while UFO's is grounded in a four-category ontology merged from Bunge-Wand-Weber conceptual-modeling work — a different philosophical lineage, the same kind of divergence mapping-001/mapping-003 already use to withhold exact-equivalence-candidate for BFO-DOLCE and BFO-UFO. Applying that same standard consistently: close-match, not exact-equivalence-candidate, for this pair too. high confidence in close-match: both the near-verbatim wording and the philosophical divergence are directly evidenced, not open questions. xwkont:ref:dolce-wonderweb-d18, xwkont:ref:ufo-2021
xwkont:mapping:continuant-occurrent:006 BFO:continuant unknown SUMO:Object none semapv:ManualMappingCuration candidate low Structural analog only: SUMO's Object sits under a physicality partition, not a temporal-persistence one. Whether SUMO:Object behaves like a continuant/endurant in practice is not confirmed by Niles & Pease (2001) alone. xwkont:ref:sumo-niles-pease-2001
xwkont:mapping:continuant-occurrent:007 BFO:occurrent unknown SUMO:Process none semapv:ManualMappingCuration candidate low Same rationale as mapping-006. xwkont:ref:sumo-niles-pease-2001
xwkont:mapping:continuant-occurrent:008 BFO:continuant close-match GFO:Presential skos:closeMatch semapv:ManualMappingCuration candidate medium Both defined by a temporal-presence criterion (BFO: wholly present at each time it exists; GFO: "exists wholly at exactly one time boundary"), but GFO's Presential is defined over discrete time-boundaries specifically, a narrower formal commitment than BFO's continuant. Medium rather than high pending a closer read of GFO's time-boundary/chronoid theory. xwkont:ref:bfo-2020, xwkont:ref:gfo
xwkont:mapping:continuant-occurrent:009 BFO:occurrent close-match GFO:Occurrent skos:closeMatch semapv:ManualMappingCuration candidate high Both sources use the identical term "occurrent" with matching temporal-extension criteria (BFO: "unfolds itself in time"; GFO: "have temporal parts... happen in time"). Highest-confidence mapping among the four new sources' correspondences, on par with the BFO/DOLCE/UFO occurrent mappings. xwkont:ref:bfo-2020, xwkont:ref:gfo
xwkont:mapping:continuant-occurrent:010 BFO:continuant close-match YAMATO:Continuant(Object) skos:closeMatch semapv:ManualMappingCuration candidate high YAMATO uses "Continuant" as its own top-level label with an explicitly stated 3D/persistence orientation, the closest terminological and conceptual match to BFO of any ADR-0015 source. Not exact-equivalence-candidate because YAMATO explicitly treats continuant and occurrent as mutually dependent rather than either being ontologically prior — a stated philosophical difference from BFO's framing. xwkont:ref:bfo-2020, xwkont:ref:yamato-mizoguchi-2010
xwkont:mapping:continuant-occurrent:011 BFO:occurrent close-match YAMATO:Occurrent(Process) skos:closeMatch semapv:ManualMappingCuration candidate high Same rationale as mapping-010, inverse pairing. YAMATO additionally distinguishes process (can change) from event (cannot) within occurrent, a finer-grained split than BFO makes explicitly at this level — noted, not resolved, per uncertainty-003. xwkont:ref:bfo-2020, xwkont:ref:yamato-mizoguchi-2010
xwkont:mapping:continuant-occurrent:012 BFO:continuant unknown TUpper:object none semapv:ManualMappingCuration candidate low Structural analog only, same rationale as SUMO's Object mapping (mapping-006): TUpper's object is defined negatively (by exclusion of timepoint/activity/activity-occurrence) rather than by a positive temporal-persistence criterion, so equivalence to BFO's continuant is not established by the definition text alone. xwkont:ref:tupper-colore
xwkont:mapping:continuant-occurrent:013 BFO:occurrent unknown TUpper:activity_occurrence none semapv:ManualMappingCuration candidate low Same rationale as mapping-012. activity_occurrence is tied to a specific activity via occurrence_of, a PSL-derived structure not obviously equivalent to BFO's broader occurrent (which also covers temporal/spatiotemporal regions). xwkont:ref:tupper-colore
xwkont:mapping:continuant-occurrent:014 BFO:continuant unknown GUM:SimpleThing none semapv:ManualMappingCuration candidate low Structural analog only, same rationale as SUMO's Object mapping (mapping-006): GUM's SimpleThing/Process split is linguistically motivated (participant vs. verb-realized "goings-on"), not a temporal-persistence criterion. xwkont:ref:gum-owl
xwkont:mapping:continuant-occurrent:015 BFO:occurrent unknown GUM:Process none semapv:ManualMappingCuration candidate low Same rationale as mapping-014. xwkont:ref:gum-owl

Uncertainty, Non-Equivalence, and Open Questions

Item ID Type Description Impact Follow-up
uncertainty-001 ~~uncertainty~~ resolved 2026-07-01 UFO's own philosophical/metaphysical grounding for its endurant/perdurant split is now confirmed directly against xwkont:ref:ufo-2021: a conceptual-modeling origin (evaluating Bunge-Wand-Weber-based approaches), later merging DOLCE and GFO on the shared basis of a four-category ontology ("the Aristotelian Square"). mapping-005 raised from medium to high; UFO's philosophical-dimension row in Source Definitions now filled with a cited paraphrase. Resolved — no further action needed.
uncertainty-002 non-equivalence SUMO's Object/Process pair is not asserted as equivalent to Continuant/Occurrent. SUMO's top-level partition criterion is physicality (Physical vs. Abstract), not temporal persistence. Low confidence on all SUMO rows in this crosswalk (mapping-006, mapping-007). Read SUMO's current source files directly (not just the 2001 founding paper) for Process's exact temporal semantics before raising confidence.
uncertainty-003 open-question This crosswalk does not resolve the Process/Event distinction within Occurrent, already flagged as an unresolved boundary in docs/releases/core-ontology-release-notes.md. Scopes this crosswalk to the Continuant/Occurrent level only. Process and Event concept crosswalks are reviewed; Process/Event boundary remains documented in release notes.
uncertainty-004 ~~uncertainty~~ resolved 2026-07-02 (scope); content buildout also completed 2026-07-02 Scope question resolved by ADR-0015: GFO, YAMATO, TUpper, and GUM (the other ontologies in xwkont:ref:borgo-galton-kutz-2022's special issue) are now in XwkOnt's source-ontology scope, alongside the original BFO/DOLCE/SUMO/UFO. The content buildout for this crosswalk (correspondences 009-016, mappings 008-015) is also now complete, directly verified against each new source's own OWL/CLIF/technical-report text. This crosswalk now covers all 8 ADR-0015 sources. The other original-inventory crosswalks have since completed the same GFO/YAMATO/TUpper/GUM buildout; all 26 reviewed concepts cover all 8 sources. No further ADR-0015 buildout action on this item — completed across the concept inventory.
uncertainty-005 open-question YAMATO's OWL/Hozo files were not fetched (registration-gated download requiring name/organization/email submission — see xwkont:ref:yamato-mizoguchi-2010); this crosswalk's YAMATO correspondences (011-012) cite section/quotation locators, not OWL class IRIs, unlike GFO/TUpper/GUM's correspondences (009-010, 013-016). The three new sources' dedicated 2022 Applied Ontology papers (YAMATO, TUpper, GUM) were also not accessed — same Cloudflare block that hit xwkont:ref:borgo-galton-kutz-2022, confirmed independently for each (HTTP 403 on direct fetch). Lower-precision locator for YAMATO than for GFO/TUpper/GUM; the three 2022 papers' comparative framing (e.g., any explicit continuant/occurrent equivalence claims the papers' authors themselves make) is unverified. If the maintainer completes YAMATO's registration form manually, fetch and cite the resulting OWL IRIs. Periodically re-check the three Applied Ontology papers in case the Cloudflare block lifts.

Provenance and References

  • xwkont:ref:bfo-2020 — Basic Formal Ontology (BFO) 2020 / ISO/IEC 21838-2:2021 — verified directly against bfo-core.ttl, 2026-07-01
  • xwkont:ref:dolce-wonderweb-d18 — WonderWeb Deliverable D18: Ontology Library (Masolo et al., 2003) — verified directly (manual PDF extraction), 2026-07-01
  • xwkont:ref:dolce-lite-owl — DOLCE-Lite OWL translation — verified directly (fetched as plain-text RDF/XML), 2026-07-01; supplies exact class IRIs for endurant/perdurant
  • xwkont:ref:ufo-2021 — UFO: Unified Foundational Ontology (Guizzardi et al., 2021) — verified directly (manual PDF extraction), 2026-07-01
  • xwkont:ref:sumo-niles-pease-2001 — Towards a Standard Upper Ontology (Niles & Pease, 2001) — verified directly against current SUMO Merge.kif, 2026-07-01
  • xwkont:ref:borgo-galton-kutz-2022 — Foundational ontologies in action (Borgo, Galton, Kutz, 2022) — unverified (full text blocked by publisher access control, not a parsing failure; see reference record's 2026-07-02 access-attempt note); only used for BFO's "realist" characterization
  • xwkont:ref:gfo — General Formal Ontology (GFO), 2024-11-18 release — verified directly (gfo.owl, modules/gfo-base.owl), 2026-07-02
  • xwkont:ref:yamato-mizoguchi-2010 — YAMATO: Yet Another More Advanced Top-level Ontology, 2010 technical report (Mizoguchi) — verified directly (manual PDF extraction), 2026-07-02; note this is not the 2022 Applied Ontology paper, which was inaccessible (Cloudflare block)
  • xwkont:ref:tupper-colore — TUpper (COLORE CLIF/OWL formalization, Grüninger) — verified directly (tupper.all.owl, tupper.clif, TUpper-Terms.html), 2026-07-02; ISO/IEC 21838-4:2023 standard text and the 2022 Applied Ontology paper not accessed
  • xwkont:ref:gum-owl — GUM: The Generalized Upper Model, OWL 3.1 (Bateman) — verified directly (GUM-31.owl, fetched via Internet Archive after confirming the canonical purl.org/net/gum2 host chain is dead), 2026-07-02; the 2022 Applied Ontology paper not accessed
  • ADR-0015 — Expand Source-Ontology Scope to Include GFO, YAMATO, TUpper, and GUM — resolves uncertainty-004; content buildout for the four new sources completed in this crosswalk 2026-07-02 (first of the 8 crosswalks to receive it)

Review History

Review ID Date Outcome Notes
xwkont:review:continuant-occurrent:2026-07-01:01 2026-07-01 Passed — advanced draftreviewed Checked against docs/governance/contributing.md's Review Checklist: scope preserved (compares source ontologies, introduces nothing new); all four source-ontology claims cite directly-verified primary sources; mapping categories/confidence values are all valid per crosswalk-methodology.md (as extended by ADR-0013); no xwkont-core:mapsTo or OWL-modeling-layer concerns (this artifact doesn't touch core.ttl); every xwkont:ref:* citation resolves to an existing reference record. One known gap — xwkont:ref:borgo-galton-kutz-2022 remains unverified, used only for BFO's "realist" philosophical characterization — is explicitly disclosed in Provenance/Future Work rather than glossed over, consistent with uncertainty being first-class content per docs/INFORMATION_ARCHITECTURE.md §7, not a defect blocking review. This was a self-review (the same work performed both the verification and this review pass), not independent third-party review; noted here rather than implied otherwise.
2026-07-02 Editorial status reverted reviewedcandidate The ADR-0015 buildout (GFO/YAMATO/TUpper/GUM correspondences 009-016, mappings 008-015, four new reference records) roughly doubled this crosswalk's Source Ontology Correspondences and Mapping Assertions content. Per docs/INFORMATION_ARCHITECTURE.md's status semantics ("reviewed" = passed review for its stated scope), a scope-expanding content addition of this size should not silently retain the prior review's status — the new content has not itself been reviewed. Awaiting a maintainer review pass before advancing back to reviewed.
xwkont:review:continuant-occurrent:2026-07-02:02 2026-07-02 Passed — advanced candidatereviewed Consolidated review pass, per docs/governance/contributing.md's Review Checklist, of the ADR-0015 buildout content across all 8 concept crosswalks. Checked: scope preserved (no new terminology or structure introduced beyond the already-decided ADR-0015 scope expansion); every xwkont:ref:* citation resolves to a real reference record; correspondence/mapping/note/uncertainty ID numbering is sequential with no gaps or duplicates; every relation-category and confidence value falls within the vocabularies docs/methodology/crosswalk-methodology.md/ADR-0013 define, and every medium-high/low-medium usage states a sourcing-driven reason in its rationale, not a general hedge; spot-checked primary-source quotations (GFO's Occurrent/Presential classes, YAMATO's continuant/occurrent passage) against the fetched artifacts and found no transcription errors. Gap found later (2026-07-06, full-corpus audit), not caught by this pass: mapping-005 (DOLCE/UFO endurant) used exact-equivalence-candidate despite note-002's own documented philosophical-lineage divergence between the two sources — the identical kind of divergence mapping-001/mapping-003 already use to withhold that category for BFO-DOLCE and BFO-UFO. This review pass checked that confidence values fell within the approved vocabulary but did not check relation-category choices for consistency against the file's own stated exclusion criterion. Corrected to close-match in the audit pass; see docs/methodology/crosswalk-runbook.md's governing principle. Self-review performed at the maintainer's explicit request, not independent third-party review.

Future Work

  • ~~Read xwkont:ref:bfo-2020 in full primary-source detail~~ — done 2026-07-01; confirmed the earlier paraphrases with exact quotations (BFO_0000002 continuant, BFO_0000003 occurrent).
  • ~~Read xwkont:ref:dolce-wonderweb-d18 and xwkont:ref:ufo-2021 in full primary-source detail~~ — done 2026-07-01, reusing extractions from object.md/role.md/process.md/relation.md; endurant/perdurant definitions confirmed for both, and UFO's philosophical grounding resolved (uncertainty-001).
  • Confirm exact IRIs/identifiers for each source term (currently unknown in Source Ontology Correspondences) — BFO IRIs now known (BFO_0000002, BFO_0000003).
  • ~~Verify SUMO's current source files directly for Process's exact temporal semantics~~ — done 2026-07-01; see process.md for the verified quotation, now cross-referenced here.
  • ~~Find or confirm a citation for UFO's philosophical grounding~~ — done 2026-07-01, uncertainty-001 resolved.
  • Find a primary or independently-verifiable source for BFO's "realist framework grounded in scientific practice" characterization, currently sourced only to the unverified xwkont:ref:borgo-galton-kutz-2022 editorial.
  • Create Process and Event concept crosswalks, building on this one — both now exist (process.md, event.md).
  • ~~Revisit whether GFO/YAMATO/TUpper/GUM should be added to XwkOnt's source-ontology scope~~ — done 2026-07-02, ADR-0015 expanded scope to all 8; this crosswalk's content buildout for the four new sources is also now complete.
  • Obtain a maintainer review pass for the 2026-07-02 buildout, to advance editorial status back from candidate to reviewed.
  • Fetch YAMATO's OWL/Hozo files if the maintainer completes the hozo.jp registration form, to replace uncertainty-005's section/quotation locators with OWL class IRIs.
  • Periodically re-check the three blocked 2022 Applied Ontology papers (YAMATO, TUpper, GUM) in case the Cloudflare/paywall block lifts.
  • ~~Extend this crosswalk's GFO/YAMATO/TUpper/GUM buildout pattern to the remaining 7 concept crosswalks (object.md, event.md, information-artifact.md, process.md, quality.md, relation.md, role.md)~~ — done; all original-inventory and later-batch crosswalks now cover all 8 ADR-0015 sources.