Claim module — relational schema

Verifiable claims are content-addressable (digest) and supported by evidence. Evidence uses class-table inheritance: a base evidence table with a subtype discriminator and three subtype child tables. verification_activity records the PROV-O activity that generates a claim.

Tables

Table	Realises	Kind	Notes
`claim`	Claim	entity	identity = `digest`; FK → `verification_activity`
`claim_evidence`	supportedBy / wasDerivedFrom `M:N`	junction	`claim` × `evidence`
`claim_assurance_level`	assuranceLevel `M:N`	junction	`claim` × `assurance_level_scheme`
`evidence`	Evidence	CTI base	`digest`; `subtype` CHECK (`sh:xone`)
`document_evidence`	DocumentEvidence	CTI child	PK = FK → `evidence`
`electronic_record_evidence`	ElectronicRecordEvidence	CTI child	PK = FK → `evidence`
`vouch_evidence`	VouchEvidence	CTI child	adds `attested_by_person_id` (`1..1`)
`verification_activity`	VerificationActivity	event	self-FK `was_informed_by_id`; FK → `trust_framework`
`trust_framework`	TrustFramework	entity	identity = framework URI

The three owl:equivalentClass aliases — Document, ElectronicRecord, Vouch — are views over the corresponding *_evidence tables, not separate tables. AssuranceLevel (a Quale-in-Region) is the assurance_level_scheme lookup, referenced through claim_assurance_level, not its own entity table.

Entity-relationship diagram

erDiagram accTitle: Claim module — entity-relationship diagram accDescr: claim supported by evidence and bound to assurance levels via junctions; evidence as a class-table-inheritance base with document, electronic-record and vouch subtype tables; verification_activity with a self re-verification chain and conformance to a trust framework. claim { uuid claim_id PK text uri UK text digest uuid verification_activity_id FK } claim_evidence { uuid claim_id PK,FK uuid evidence_id PK,FK } claim_assurance_level { uuid claim_id PK,FK text assurance_level_notation PK,FK } evidence { uuid evidence_id PK text uri UK text digest text subtype } document_evidence { uuid evidence_id PK,FK } electronic_record_evidence { uuid evidence_id PK,FK } vouch_evidence { uuid evidence_id PK,FK uuid attested_by_person_id FK } verification_activity { uuid verification_activity_id PK text uri UK uuid conforms_to_trust_framework_id FK uuid was_informed_by_id FK timestamptz ended_at_time } trust_framework { uuid trust_framework_id PK text uri UK } claim ||--o{ claim_evidence : "supported by" evidence ||--o{ claim_evidence : "supports" claim ||--o{ claim_assurance_level : "assurance level" claim }o--o| verification_activity : "generated by" evidence ||--o| document_evidence : "subtype" evidence ||--o| electronic_record_evidence : "subtype" evidence ||--o| vouch_evidence : "subtype" vouch_evidence }o--|| person : "attested by" verification_activity }o--o| trust_framework : "conforms to" verification_activity ||--o{ verification_activity : "was informed by"

Lookup tables

Lookup	Bound by	Members
`assurance_level_scheme`	`claim_assurance_level.assurance_level_notation`	4
`evidence_method`	aligns subtypes via `skos:exactMatch`	3

Mapping notes

Evidence is content-addressable. Both claim and evidence are keyed on digest, not an auto-increment id — identical content must not exist as two rows.
Class-table inheritance with sh:xone. The evidence.subtype discriminator plus one child table per subtype realises “exactly one subtype”. Only vouch_evidence adds a mandatory facet (attested_by_person_id, 1..1).
Aliases are views, not tables. Document, ElectronicRecord, and Vouch are the same OWL identity as the *_evidence long names.
Re-verification is a self-chain. verification_activity.was_informed_by_id references the prior activity (prov:wasInformedBy); the claim’s verification_activity_id realises prov:wasGeneratedBy. (person lives in the agent module.)

Cross-tier

Logical tier: claim module.