Annotation

Who said it, and when.

rdf12-annotation.js · output · proof · check · try it in the playground

The question

The data says Alice’s name is “Alice”. It also has a reifier, claim1, that stands for that statement through rdf:reifies and records that Carol stated it on 15 January 2025. That is how RDF 1.2 annotates a triple.

Can we recover the statement together with its annotations?

What we tell eyecode

implies(
  [
    rdf(S, P, O, 'default_graph'),                                // asserted
    rdf(Reifier, iri(reifies), triple(S, P, O), 'default_graph'), // and reified
    rdf(Reifier, iri(ex + 'statedBy'), Source, 'default_graph'),
    rdf(Reifier, iri(ex + 'recorded'), Date, 'default_graph'),
  ],
  annotated_claim(S, P, O, Reifier, Source, Date),
)

A second rule writes each annotated claim back as four quads.

RDF values are ordinary terms: iri(Text) for an IRI, literal(Text, datatype(IRI)) or literal(Text, lang(Tag)) for a literal, triple(S, P, O) for a triple term, and rdf(S, P, O, Graph) for a quad in a graph, 'default_graph' or iri(Name).

The date stays literal('2025-01-15', datatype(xsd + 'date')): its text and its datatype travel together, so it returns to RDF unchanged.

What eyecode concludes

The triple with its reifier and both annotations:

result_rdf(iri('https://example.org/alice'), iri('https://example.org/name'), literal('Alice', datatype('http://www.w3.org/2001/XMLSchema#string')), 'default_graph')
result_rdf(iri('https://example.org/claim1'), iri('http://www.w3.org/1999/02/22-rdf-syntax-ns#reifies'), triple(iri('https://example.org/alice'), iri('https://example.org/name'), literal('Alice', datatype('http://www.w3.org/2001/XMLSchema#string'))), 'default_graph')
result_rdf(iri('https://example.org/claim1'), iri('https://example.org/statedBy'), iri('https://example.org/carol'), 'default_graph')
result_rdf(iri('https://example.org/claim1'), iri('https://example.org/recorded'), literal('2025-01-15', datatype('http://www.w3.org/2001/XMLSchema#date')), 'default_graph')

Why: the proof in plain words

1. Alice’s name is “Alice”, claim1 reifies that triple, Carol stated it and it was recorded on 2025-01-15 — facts 1 to 4.
2. So it is an annotated claim — rule 5, which needs the triple to be asserted as well as reified.
3. So the four quads follow — rule 6.

Each step names the exact line of the program it used, and the values it filled in.

Checked, not just claimed

The proof is a document of its own, and a separate checker reads it against the program. It confirms that every step is an instance of the line it cites, that nothing is assumed the program does not say, that no step depends on itself, and that every step serves one of the results.

Verdict: checked. All 9 steps verified, and nothing taken on trust.

Try it

eyecode examples/rdf12-annotation.js                        # the results as quads
eyecode --proof examples/rdf12-annotation.js                # with their proof
eyecode examples/rdf12-annotation.js > out.js && eyecode-to-rdf out.js -o out.ttl

eyecode-to-rdf and rdf-to-eyecode come with rdf-interchange; they turn eyecode’s quads into RDF and RDF into quads. Or open it in the playground. Remove the asserted name triple and run again: the reifier alone is not enough, and nothing follows.

Takeaway

An annotation is data about a statement, and rules can insist that the statement itself holds before they use it.