BuildingEquipment
type: Class
description: Equipment installed in or serving a building.

ComparisonDimension
type: Class
description: A criterion used to compare the two graph architectures.

EvidenceDocument
type: Class
description: A source document that supports a validation decision.
subclass of: CreativeWork

GraphArchitecture
type: Class
description: A graph-platform architecture participating in the comparison.

GraphLayer
type: Class
description: A logical layer of the real-estate knowledge system.

HeatPump
type: Class
description: A heat-pump asset used for building heating or cooling.
subclass of: BuildingEquipment
equivalent class: Heat pump

InvoiceLineItem
type: Class
description: A named line item on an invoice.

PlatformCapability
type: Class
description: A graph-platform capability demonstrated or described in the comparison.

RetrievalCandidate
type: Class
description: A candidate ontology term selected by graph patterns and instance evidence.

RetrievalExecution
type: Class
description: A provenance-bearing execution or reproducible result of a retrieval mode.

RetrievalMode
type: Class
description: A defined method for retrieving or ranking knowledge-graph entities.

ValidationFinding
type: Class
description: A named result produced by evaluating a validation rule.
subclass of: Review

ValidationRule
type: Class
description: A deterministic constraint or graph rule evaluated against business evidence.

Building
type: Class
description: Shared building concept aligned across the real-estate and building-equipment domains.
inLayer: OntologyLayer

Heat pump
type: Class
description: Building equipment that transfers heat for heating or cooling.
subclass of: Building
inLayer: OntologyLayer

Invoice
type: Class
description: Commercial document requesting payment for supplied goods or services.
inLayer: OntologyLayer

Legal requirement
type: Class
description: Requirement grounded in an identified legal or regulatory source.
inLayer: OntologyLayer

Service contract
type: Class
description: Agreement defining covered maintenance and diagnostic services.
inLayer: OntologyLayer

Warranty
type: Class
description: Commitment covering qualifying equipment defects or services during a defined period.
inLayer: OntologyLayer

Call-out ceiling shape
type: NodeShape
about: Service call-out ceiling rule
description: Invoice total should not exceed the contracted call-out ceiling.
sparql: Call-out ceiling shape constraint
target class: Invoice
inLayer: RulesLayer

Covered-service billing shape
type: NodeShape
about: Covered-service billing rule
description: Covered diagnostic service must not be billed as a separate charge.
sparql: Covered-service billing shape constraint
target class: Invoice
inLayer: RulesLayer

Duplicate invoice identifier shape
type: NodeShape
about: Duplicate invoice identifier rule
description: Supplier invoice identifiers should be unique.
sparql: Duplicate invoice identifier shape constraint
target class: Invoice
inLayer: RulesLayer

evaluatesRule
type: Property
description: Links a finding to its evaluated validation rule.
domain: ValidationFinding
range: ValidationRule

expectedAmount
type: Property
description: Expected monetary amount derived from contract or line-item evidence.
domain: Resource
range: decimal

findingStatus
type: Property
description: Records Pass, Warning, or Fail for a validation finding.
domain: ValidationFinding
range: string

focusNode
type: Property
description: Identifies the primary business entity evaluated by a finding.
domain: ValidationFinding
range: Resource

hasEvidence
type: Property
description: Links a finding to the evidence that supports it.
domain: ValidationFinding
range: Resource

implementsArchitecture
type: Property
description: Associates an execution or component with its graph architecture.
domain: Resource
range: GraphArchitecture

inLayer
type: Property
description: Associates an entity with one logical graph layer.
domain: Resource
range: GraphLayer

Invoice validation shape
type: NodeShape
about: Invoice arithmetic rule
description: Invoice total must reconcile with line items and tax.
sparql: Invoice validation shape constraint
target class: Invoice
inLayer: RulesLayer

matchedTerm
type: Property
description: Connects a ranked result to the matched ontology term.
domain: RetrievalCandidate
range: Resource

neo4jTreatment
type: Property
description: Describes how the article's Neo4j implementation treats a comparison dimension.
domain: ComparisonDimension
range: string

observedAmount
type: Property
description: Observed monetary amount supplied by the invoice.
domain: Resource
range: decimal

Rhein Main demonstration property portfolio
type: Collection
description: Illustrative property portfolio used solely for the proof of concept.
has part: Lindenhof Property

semanticScore
type: Property
description: Score contributed by RDF type and graph-pattern constraints.
domain: RetrievalCandidate
range: decimal

supportsCapability
type: Property
description: Connects an architecture to a demonstrated or source-described capability.
domain: GraphArchitecture
range: PlatformCapability

usesRetrievalMode
type: Property
description: Associates an execution with its retrieval mode.
domain: RetrievalExecution
range: RetrievalMode

virtuosoTreatment
type: Property
description: Describes how the Virtuoso proof of concept treats a comparison dimension.
domain: ComparisonDimension
range: string

rdf-infographic-skill
type: SoftwareApplication
type: SoftwareAgent
description: Reusable OpenLink AI-agent skill used to generate, query, or present the RDF collection.
acted on behalf of: this

Codex
type: SoftwareApplication
type: SoftwareAgent
description: OpenAI coding agent environment used with GPT-5 Chat to generate this collection.
acted on behalf of: this

Irina Adamchic, PhD
type: Person
description: Article author and knowledge-graph architect who presents the Neo4j-based layered real-estate proof of concept.
job title: AI Manager; Knowledge Graph Architect

Akoma Ntoso (OASIS)
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for legal document structure.
inLayer: OntologyLayer

ASK Arithmetic
type: SoftwareSourceCode
code sample type: Executable
description: Executable standards-based SPARQL ASK proof over the companion Turtle graph.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> ASK WHERE { :invoiceRE20260017 schema:totalPaymentDue 476.00 ; schema:tax 76.00 ; schema:hasPart :lineDiagnostic, :lineFilter, :lineTravel . :lineDiagnostic :observedAmount 120.00 . :lineFilter :observedAmount 180.00 . :lineTravel :observedAmount 100.00 . }

ASK Asset
type: SoftwareSourceCode
code sample type: Executable
description: Executable standards-based SPARQL ASK proof over the companion Turtle graph.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> ASK WHERE { VALUES ?document { :invoiceRE20260017 :installationRecord :warranty :serviceContract } ?document schema:about :heatPumpHPDE2048 . }

ASK CoveredDiagnostic violation
type: SoftwareSourceCode
code sample type: Executable
description: Executable standards-based SPARQL ASK proof over the companion Turtle graph.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> ASK WHERE { :invoiceRE20260017 schema:hasPart :lineDiagnostic . :lineDiagnostic :observedAmount ?amount . FILTER(?amount > 0) :serviceContract schema:about :heatPumpHPDE2048 . }

ASK Duplicate
type: SoftwareSourceCode
code sample type: Executable
description: Executable standards-based SPARQL ASK proof over the companion Turtle graph.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> ASK WHERE { :invoiceRE20260017 schema:identifier ?id ; schema:provider ?supplier . :priorInvoiceRE20260017 schema:identifier ?id ; schema:provider ?supplier . FILTER(:invoiceRE20260017 != :priorInvoiceRE20260017) }

ASK evidence path
type: SoftwareSourceCode
code sample type: Executable
description: Executable standards-based SPARQL ASK proof over the companion Turtle graph.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> ASK WHERE { :finding5 :focusNode :invoiceRE20260017 ; :hasEvidence :lineDiagnostic, :serviceContract ; :evaluatesRule :ruleCoveredDiagnostic . :lineDiagnostic schema:about :heatPumpHPDE2048 . :serviceContract schema:about :heatPumpHPDE2048 . }

ASK Supplier
type: SoftwareSourceCode
code sample type: Executable
description: Executable standards-based SPARQL ASK proof over the companion Turtle graph.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> ASK WHERE { :invoiceRE20260017 schema:provider ?supplier . :installationContract schema:provider ?supplier . :serviceContract schema:provider ?supplier . }

Brick Schema
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for buildings, hvac, and equipment.
inLayer: OntologyLayer

Call-out ceiling shape constraint
type: SPARQLConstraint
description: Invoice total should not exceed the contracted call-out ceiling.
message: Invoice total should not exceed the contracted call-out ceiling.
inLayer: RulesLayer

One problem, two competing graph architectures
type: CreativeWork
description: The proof of concept holds the real-estate evidence constant and contrasts the article's Neo4j design with an RDF-native Virtuoso implementation. The comparison concerns concrete architectures rather than claiming that every Neo4j deployment lacks semantic integrations.
has part: Graph model
has part: Entity identity
has part: Inference
has part: Layer representation
has part: Portability
has part: Provenance
has part: Pure SPARQL proof
has part: Query surface
has part: Rules and validation
has part: Domain schema
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
position: 2
text: The proof of concept holds the real-estate evidence constant and contrasts the article's Neo4j design with an RDF-native Virtuoso implementation. The comparison concerns concrete architectures rather than claiming that every Neo4j deployment lacks semantic integrations.

Covered-service billing shape constraint
type: SPARQLConstraint
description: Covered diagnostic service must not be billed as a separate charge.
message: Covered diagnostic service must not be billed as a separate charge.
inLayer: RulesLayer

Custom ontology
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for project-specific types.
inLayer: OntologyLayer

Cypher graph querying
type: PlatformCapability
description: Property-graph query surface used by the article's implementation.
implementsArchitecture: Neo4j Linked Property Graph architecture

Graph model
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of graph model across the two concrete implementations.
neo4jTreatment: Linked Property Graph with labeled nodes and relationships.
virtuosoTreatment: RDF quad model with IRI-identified subjects, predicates, objects, and optional graph names.

Entity identity
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of entity identity across the two concrete implementations.
neo4jTreatment: Internal graph identifiers and URI properties support identity within the property graph.
virtuosoTreatment: HTTP IRIs are native identifiers for entities and predicates and can be dereferenced through a Linked Data resolver.

Inference
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of inference across the two concrete implementations.
neo4jTreatment: Additional semantic inference depends on modeling conventions, application logic, or added integrations.
virtuosoTreatment: RDFS/OWL axioms can entail additional facts while remaining visible and queryable as graph semantics.

Layer representation
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of layer representation across the two concrete implementations.
neo4jTreatment: Neo4j labels and architectural conventions identify OntologyLayer, LegalLayer, ContractsLayer, InvoiceLayer, and RulesLayer.
virtuosoTreatment: Named layer resources and inLayer predicates make layer membership queryable while retaining shared entity identity.

Portability
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of portability across the two concrete implementations.
neo4jTreatment: Graph Builder, APOC, Neo4j vector indexes, and Cypher are Neo4j-specific implementation choices.
virtuosoTreatment: RDF, RDFS, OWL, SHACL, SPARQL, and HTTP IRIs are standards-based and portable across conforming systems.

Provenance
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of provenance across the two concrete implementations.
neo4jTreatment: Application-specific properties and traversal history can record lineage.
virtuosoTreatment: PROV-O activities and named evidence relationships connect every result to its sources and generating mode.

Pure SPARQL proof
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of pure sparql proof across the two concrete implementations.
neo4jTreatment: The article uses a Neo4j vector index to pre-filter OntologyLayer nodes.
virtuosoTreatment: The RDF proof of concept demonstrates the same business scenario with standards-based SPARQL 1.1 patterns and no vector-function dependency.

Query surface
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of query surface across the two concrete implementations.
neo4jTreatment: Cypher plus Neo4j procedures and indexes.
virtuosoTreatment: Pure SPARQL graph patterns over ontology instances, layers, rules, evidence, and findings.

Rules and validation
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of rules and validation across the two concrete implementations.
neo4jTreatment: RulesLayer and application/agent traversal evaluate business conditions.
virtuosoTreatment: Named RDF rules, SHACL constraints, SPARQL ASK checks, and provenance-bearing findings.

Domain schema
type: ComparisonDimension
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
description: Comparison of domain schema across the two concrete implementations.
neo4jTreatment: Fixed Entity Architecture projects ontology concepts into LPG labels and properties.
virtuosoTreatment: RDF/OWL ontology terms remain native graph resources with domains, ranges, hierarchy, and dereferenceable identifiers.

Duplicate invoice identifier shape constraint
type: SPARQLConstraint
description: Supplier invoice identifiers should be unique.
message: Supplier invoice identifiers should be unique.
inLayer: RulesLayer

FIBO (EDM Council)
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for finance and legal-business concepts.
inLayer: OntologyLayer

PASS: Invoice arithmetic rule
type: ValidationFinding
description: Line items sum to EUR 400.00; tax is EUR 76.00; total due is EUR 476.00.
evaluatesRule: Invoice arithmetic rule
findingStatus: PASS
focusNode: Invoice RE-2026-0017
hasEvidence: Invoice RE-2026-0017
hasEvidence: Diagnostic inspection
hasEvidence: Replacement filter
hasEvidence: Technician travel
inLayer: RulesLayer

PASS: Supplier identity rule
type: ValidationFinding
description: The invoice provider matches the contractor identified by the installation and service contracts.
evaluatesRule: Supplier identity rule
findingStatus: PASS
focusNode: Invoice RE-2026-0017
hasEvidence: ThermoHaus Service
hasEvidence: Heat-pump installation contract
hasEvidence: Invoice RE-2026-0017
hasEvidence: Annual heat-pump service contract
inLayer: RulesLayer

PASS: Equipment identity rule
type: ValidationFinding
description: The invoice, installation record, warranty, and service contract all concern heat pump HP-DE-2048.
evaluatesRule: Equipment identity rule
findingStatus: PASS
focusNode: Invoice RE-2026-0017
hasEvidence: Heat pump HP-DE-2048
hasEvidence: Installation record for HP-DE-2048
hasEvidence: Invoice RE-2026-0017
hasEvidence: Annual heat-pump service contract
hasEvidence: Heat-pump warranty
inLayer: RulesLayer

PASS: Warranty-period rule
type: ValidationFinding
description: The invoice date falls within the illustrative warranty validity period.
evaluatesRule: Warranty-period rule
findingStatus: PASS
focusNode: Invoice RE-2026-0017
hasEvidence: Invoice RE-2026-0017
hasEvidence: Heat-pump warranty
inLayer: RulesLayer

FAIL: Covered-service billing rule
type: ValidationFinding
description: The diagnostic line is billed even though the annual service contract says that diagnostic visit is covered.
evaluatesRule: Covered-service billing rule
findingStatus: FAIL
focusNode: Invoice RE-2026-0017
hasEvidence: Invoice RE-2026-0017
hasEvidence: Diagnostic inspection
hasEvidence: Annual heat-pump service contract
inLayer: RulesLayer

WARNING: Duplicate invoice identifier rule
type: ValidationFinding
description: A prior invoice record uses the same supplier invoice identifier.
evaluatesRule: Duplicate invoice identifier rule
findingStatus: WARNING
focusNode: Invoice RE-2026-0017
hasEvidence: Invoice RE-2026-0017
hasEvidence: Prior invoice record RE-2026-0017
inLayer: RulesLayer

WARNING: Service call-out ceiling rule
type: ValidationFinding
description: The total invoice amount of EUR 476.00 exceeds the illustrative EUR 450.00 call-out ceiling.
evaluatesRule: Service call-out ceiling rule
findingStatus: WARNING
focusNode: Invoice RE-2026-0017
hasEvidence: Invoice RE-2026-0017
hasEvidence: Annual heat-pump service contract
inLayer: RulesLayer

PASS: Tax evidence rule
type: ValidationFinding
description: The invoice includes an explicit tax amount and the legal evidence node is connected to the rule.
evaluatesRule: Tax evidence rule
findingStatus: PASS
focusNode: Invoice RE-2026-0017
hasEvidence: Invoice RE-2026-0017
hasEvidence: Illustrative German invoice and tax evidence record
hasEvidence: Invoice tax evidence requirement
inLayer: RulesLayer

Fixed Entity Architecture
type: PlatformCapability
description: Source pattern that projects selected ontology concepts into a stable Linked Property Graph entity layer.
implementsArchitecture: Neo4j Linked Property Graph architecture

Invoice validation shape constraint
type: SPARQLConstraint
description: Invoice total must reconcile with line items and tax.
message: Invoice total must reconcile with line items and tax.
inLayer: RulesLayer

data-twingler KG-only mode
type: RetrievalMode
description: RDF-grounded retrieval that answers from the generated ontology instances, graph structure, rules, and local evidence without vector or full-text functions.
instrument: data-twingler skill

LKIF-Core
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for legal concepts.
inLayer: OntologyLayer

Neo4j vector index
type: PlatformCapability
description: Source mechanism used to find the top-k ontology-layer nodes for a document chunk.
implementsArchitecture: Neo4j Linked Property Graph architecture

P2P-O (DFKI)
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for procure-to-pay and invoices.
inLayer: OntologyLayer

PROV-O evidence lineage
type: PlatformCapability
description: Named provenance links from retrieval and validation results back to evidence and execution activities.
implementsArchitecture: Virtuoso RDF knowledge-graph architecture

Pure SPARQL covered-service evidence path
type: SoftwareSourceCode
code sample type: Executable
description: Shows the failed covered-service path from finding to invoice, billed diagnostic line, service contract, and rule using pure SPARQL.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> SELECT ?finding ?invoice ?lineItem ?lineName ?lineAmount ?serviceContract ?contractText ?rule FROM <https://linkeddata.uriburner.com/DAV/demos/daas/power-layered-knowledge-graphs-real-estate-neo4j-virtuoso-gpt5-chat-1.ttl> WHERE { ?finding :evaluatesRule :ruleCoveredDiagnostic ; :focusNode ?invoice ; :hasEvidence ?lineItem, ?serviceContract ; :evaluatesRule ?rule . ?invoice a schema:Invoice ; schema:hasPart ?lineItem . ?lineItem a :InvoiceLineItem ; schema:name ?lineName ; :observedAmount ?lineAmount . ?serviceContract schema:about :heatPumpHPDE2048 ; schema:description ?contractText . FILTER(?lineAmount > 0) } ORDER BY ?finding ?lineItem

Pure SPARQL invoice instance details
type: SoftwareSourceCode
code sample type: Executable
description: Retrieves the proof-of-concept invoice instance, line items, amounts, asset, supplier, tax, and total without vector or full-text functions.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> SELECT ?invoice ?invoiceName ?lineItem ?lineName ?lineAmount ?tax ?total ?asset ?supplier FROM <https://linkeddata.uriburner.com/DAV/demos/daas/power-layered-knowledge-graphs-real-estate-neo4j-virtuoso-gpt5-chat-1.ttl> WHERE { ?invoice a schema:Invoice ; schema:name ?invoiceName ; schema:hasPart ?lineItem ; schema:about ?asset ; schema:provider ?supplier ; schema:tax ?tax ; schema:totalPaymentDue ?total . ?lineItem a :InvoiceLineItem ; schema:name ?lineName ; :observedAmount ?lineAmount . } ORDER BY ?invoice ?lineName

Pure SPARQL layer inventory
type: SoftwareSourceCode
code sample type: Executable
description: Lists each generated GraphLayer and its ontology, evidence, invoice, and rule members using only SPARQL graph patterns.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> SELECT ?layer ?layerName ?member ?memberName ?memberType FROM <https://linkeddata.uriburner.com/DAV/demos/daas/power-layered-knowledge-graphs-real-estate-neo4j-virtuoso-gpt5-chat-1.ttl> WHERE { ?layer a :GraphLayer ; schema:name ?layerName ; schema:hasPart ?member . OPTIONAL { ?member schema:name ?memberName . } OPTIONAL { ?member a ?memberType . } } ORDER BY ?layerName ?memberName ?member

Pure SPARQL validation findings
type: SoftwareSourceCode
code sample type: Executable
description: Returns the named validation findings, statuses, evaluated rules, focus node, and evidence resources using ordinary SPARQL.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> SELECT ?finding ?findingName ?status ?rule ?ruleName ?focusNode ?evidence ?evidenceName FROM <https://linkeddata.uriburner.com/DAV/demos/daas/power-layered-knowledge-graphs-real-estate-neo4j-virtuoso-gpt5-chat-1.ttl> WHERE { ?finding a :ValidationFinding ; schema:name ?findingName ; :findingStatus ?status ; :evaluatesRule ?rule ; :focusNode ?focusNode ; :hasEvidence ?evidence . OPTIONAL { ?rule schema:name ?ruleName . } OPTIONAL { ?evidence schema:name ?evidenceName . } } ORDER BY ?status ?findingName ?evidenceName

RDF HTTP IRI identity
type: PlatformCapability
description: Virtuoso design capability in which entities and predicates are identified natively by HTTP IRIs.
implementsArchitecture: Virtuoso RDF knowledge-graph architecture

RDF inference
type: PlatformCapability
description: Derivation of additional facts from explicit RDFS/OWL axioms and graph semantics.
implementsArchitecture: Virtuoso RDF knowledge-graph architecture

RealEstateCore
type: CreativeWork
about: OntologyLayer
description: Article-listed ontology source for buildings and real estate.
inLayer: OntologyLayer

Executed pure SPARQL evidence
type: CreativeWork
description: Standards-based RDF and SPARQL checks are executed locally. The proof of concept intentionally excludes SPARQL queries that depend on vector functions so the showcase is portable across SPARQL 1.1 processors.
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
position: 5
text: Standards-based RDF and SPARQL checks are executed locally. The proof of concept intentionally excludes SPARQL queries that depend on vector functions so the showcase is portable across SPARQL 1.1 processors.

Schema selection: vector GraphRAG versus pure SPARQL
type: CreativeWork
description: The article's Cypher vector query is preserved as source evidence. The Virtuoso/RDF proof of concept uses pure SPARQL graph patterns over generated ontology instances, invoice evidence, layer membership, rules, and validation findings.
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
position: 4
text: The article's Cypher vector query is preserved as source evidence. The Virtuoso/RDF proof of concept uses pure SPARQL graph patterns over generated ontology instances, invoice evidence, layer membership, rules, and validation findings.

Source Neo4j GraphRAG ontology pre-filter
type: SoftwareSourceCode
code sample type: Source query
description: Cypher query reproduced from the LinkedIn article for top-k vector retrieval over OntologyLayer nodes.
is part of: Reproducible query and validation recipes
programming language: Cypher
target: Neo4j
text: CALL db.index.vector.queryNodes($index_name, $k, $embedding) YIELD node AS vectorNode, score AS vectorScore WITH vectorNode, vectorScore WHERE vectorNode:OntologyLayer AND vectorNode.name IS NOT NULL RETURN vectorNode.name AS name, coalesce(vectorNode.uri, '') AS uri, coalesce(vectorNode.kind, 'class') AS kind, coalesce(vectorNode.ontologies, []) AS ontologies, vectorScore AS score ORDER BY vectorScore DESC

What the source article builds
type: CreativeWork
description: The article presents a Neo4j Community Edition proof of concept in which a Fixed Entity Architecture imports selected ontology concepts into a Linked Property Graph, organizes evidence into five layers, and uses vector-based GraphRAG to pre-filter ontology terms before document extraction.
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
position: 1
text: The article presents a Neo4j Community Edition proof of concept in which a Fixed Entity Architecture imports selected ontology concepts into a Linked Property Graph, organizes evidence into five layers, and uses vector-based GraphRAG to pre-filter ontology terms before document extraction.

SPARQL graph querying
type: PlatformCapability
description: Standards-based query surface for graph patterns, named graphs, provenance, and federation.
implementsArchitecture: Virtuoso RDF knowledge-graph architecture

Evidence path
type: DefinedTerm
description: Connected subgraph that explains how a finding follows from business documents, assets, rules, and provenance.
in defined term set: Layered graph comparison glossary

Fixed Entity Architecture
type: DefinedTerm
description: The source author's pattern for a stable entity layer that projects selected ontology concepts into a property graph.
in defined term set: Layered graph comparison glossary

GraphRAG
type: DefinedTerm
description: Retrieval-augmented generation that uses graph structure or graph retrieval as part of context selection.
in defined term set: Layered graph comparison glossary

RDF inference
type: DefinedTerm
description: Derivation of additional RDF statements from explicit axioms and entailment rules.
in defined term set: Layered graph comparison glossary

KG-only retrieval
type: DefinedTerm
description: Resolution from local RDF graph evidence and semantics without endpoint corroboration.
in defined term set: Layered graph comparison glossary

Linked Property Graph
type: DefinedTerm
description: Property-graph model using labeled nodes, relationships, and properties, with explicit links between entities.
in defined term set: Layered graph comparison glossary

Named graph
type: DefinedTerm
description: RDF graph identified by an IRI so statements can be grouped, queried, and attributed.
in defined term set: Layered graph comparison glossary

OntologyLayer
type: DefinedTerm
description: Layer containing stable domain terms used to guide extraction and connect other layers.
in defined term set: Layered graph comparison glossary

Provenance
type: DefinedTerm
description: Information identifying the origin, transformation, evidence, and responsible activity behind a graph assertion or result.
in defined term set: Layered graph comparison glossary

Pure SPARQL proof
type: DefinedTerm
description: A proof path that uses standards-based SPARQL graph patterns over RDF instances without full-text or vector-function extensions.
in defined term set: Layered graph comparison glossary

Resource Description Framework
type: DefinedTerm
description: W3C graph data model using IRI-identified subjects, predicates, and objects.
in defined term set: Layered graph comparison glossary

Shapes Constraint Language
type: DefinedTerm
description: RDF vocabulary for expressing and reporting graph-shape constraints.
in defined term set: Layered graph comparison glossary

Virtuoso KG-only ontology-slice query
type: SoftwareSourceCode
code sample type: Executable
description: Deterministic RDF graph-pattern query selecting the ontology slice required for the heat-pump invoice scenario.
is part of: Reproducible query and validation recipes
programming language: SPARQL
target: OpenLink Virtuoso
text: PREFIX schema: <http://schema.org/> PREFIX : <https://www.linkedin.com/pulse/power-layered-knowledge-graphs-applied-real-estate-adamchic-phd-vv4df/#> SELECT ?term ?name ?sourceOntology FROM <https://linkeddata.uriburner.com/DAV/demos/daas/power-layered-knowledge-graphs-real-estate-neo4j-virtuoso-gpt5-chat-1.ttl> WHERE { ?term :inLayer :ontologyLayer ; schema:name ?name . OPTIONAL { ?sourceOntology schema:hasPart ?term } VALUES ?term { :heatPumpConcept :invoiceConcept :serviceContractConcept :warrantyConcept :legalRequirementConcept } } ORDER BY ?name

Neo4j
type: SoftwareApplication
description: Graph database used by the source article's proof of concept.

data-twingler skill
type: SoftwareApplication
type: SoftwareAgent
description: Reusable OpenLink AI-agent skill used to generate, query, or present the RDF collection.
acted on behalf of: this

kg-generator skill
type: SoftwareApplication
type: SoftwareAgent
description: Reusable OpenLink AI-agent skill used to generate, query, or present the RDF collection.
acted on behalf of: this

Answer 1
type: Answer
is part of: What is the article's central architectural claim?
text: A smart layered graph can serve as a reusable knowledgebase foundation for multiple real-estate and agentic use cases rather than solving only one retrieval problem.

Answer 10
type: Answer
is part of: Why is the duplicate invoice only a warning?
text: The matching identifier is suspicious evidence requiring review, but the small illustrative graph does not establish whether the earlier record was canceled, corrected, or legitimately reissued.

Answer 11
type: Answer
is part of: Does this collection provide legal advice?
text: No. Legal nodes are illustrative evidence used to demonstrate graph linkage and validation mechanics, not a complete or authoritative statement of German law.

Answer 12
type: Answer
is part of: Does the comparison claim every Neo4j system lacks semantics?
text: No. It compares the article's concrete LPG projection with the RDF-native Virtuoso proof of concept and acknowledges that Neo4j can be extended or integrated with semantic tooling.

Answer 13
type: Answer
is part of: What makes an RDF finding auditable?
text: Each named finding records its rule, focus node, status, explanation, and direct links to the invoice, contract, asset, or legal evidence supporting it.

Answer 14
type: Answer
is part of: How does the graph remain layered without duplicating entities?
text: Entities retain one stable IRI while explicit inLayer relations and cross-layer evidence links make their logical placement and reuse queryable.

Answer 2
type: Answer
is part of: What does Fixed Entity Architecture do in the source implementation?
text: It projects selected ontology concepts into a stable Neo4j entity layer so later document extraction can attach to a controlled domain schema.

Answer 3
type: Answer
is part of: Why is Virtuoso treated as a head-on competitor?
text: Virtuoso is an RDF quad-store and multi-model database that can provide graph storage, query, inference-oriented semantics, provenance, and federation through SPARQL.

Answer 4
type: Answer
is part of: What is KG-only mode in this collection?
text: KG-only resolves answers from RDF graph structure, semantics, rules, and local evidence without depending on a live endpoint or vector retrieval.

Answer 5
type: Answer
is part of: Why remove vector-function SPARQL from this edition?
text: This edition isolates the RDF proof of concept: every workbench query is pure SPARQL over generated ontology instances, rules, findings, and evidence paths.

Answer 6
type: Answer
is part of: Does the proof require Virtuoso vector functions?
text: No. The proof-of-concept queries use standards-based SPARQL 1.1 graph patterns. Virtuoso remains the RDF-native target, but this workbench avoids vector-specific functions.

Answer 7
type: Answer
is part of: Was the pure SPARQL proof executed during generation?
text: Yes. The Turtle parse, standards-based SPARQL ASK validations, inference checks, graph-data extraction, HTML validation, and browser interaction checks are executed locally.

Answer 8
type: Answer
is part of: Which parts were executed?
text: The Turtle parse, six SPARQL ASK validations, inference checks, graph-data extraction, HTML validation, and browser interaction checks are executed locally.

Answer 9
type: Answer
is part of: What invoice defect does the proof of concept find?
text: It finds that a diagnostic line was billed even though the illustrative annual service contract identifies that diagnostic visit as covered.

Heat-pump installation contract
type: EvidenceDocument
about: Lindenhof Building A
about: Heat pump HP-DE-2048
description: Illustrative contract identifying the installed asset, supplier, and agreed work.
provider: ThermoHaus Service
inLayer: ContractsLayer

Installation record for HP-DE-2048
type: EvidenceDocument
about: Lindenhof Building A
about: Heat pump HP-DE-2048
description: Illustrative installation evidence connecting the building, equipment serial number, contractor, and installation date.
provider: ThermoHaus Service
inLayer: ContractsLayer

Prior invoice record RE-2026-0017
type: Invoice
description: Illustrative prior record sharing the same supplier invoice identifier and triggering a duplicate warning.
provider: ThermoHaus Service
inLayer: InvoiceLayer

Lindenhof Property
type: Accommodation
description: Illustrative multi-unit property containing the heat-pump asset.
has part: Lindenhof Building A

Equipment identity rule
type: ValidationRule
description: The invoice, installation record, warranty, and service contract all concern heat pump HP-DE-2048.
inLayer: RulesLayer

Supplier identity rule
type: ValidationRule
description: The invoice provider matches the contractor identified by the installation and service contracts.
inLayer: RulesLayer

Tax evidence rule
type: ValidationRule
description: The invoice includes an explicit tax amount and the legal evidence node is connected to the rule.
inLayer: RulesLayer

Warranty-period rule
type: ValidationRule
description: The invoice date falls within the illustrative warranty validity period.
inLayer: RulesLayer

Load the companion Turtle graph
type: HowToStep
description: Parse the Turtle document or load it into Virtuoso under the documented graph IRI.
is part of: How to reproduce the Neo4j-versus-Virtuoso comparison
position: 1
text: Parse the Turtle document or load it into Virtuoso under the documented graph IRI.

Inspect the five source layers
type: HowToStep
description: Query the named GraphLayer resources and their members before evaluating the business scenario.
is part of: How to reproduce the Neo4j-versus-Virtuoso comparison
position: 2
text: Query the named GraphLayer resources and their members before evaluating the business scenario.

Run KG-only semantic selection
type: HowToStep
description: Execute the deterministic SPARQL graph-pattern query to retrieve the ontology slice required by the invoice scenario.
is part of: How to reproduce the Neo4j-versus-Virtuoso comparison
position: 3
text: Execute the deterministic SPARQL graph-pattern query to retrieve the ontology slice required by the invoice scenario.

Run the validation ASK queries
type: HowToStep
description: Execute the arithmetic, supplier, asset, covered-service, duplicate-identifier, and evidence-path ASK queries.
is part of: How to reproduce the Neo4j-versus-Virtuoso comparison
position: 4
text: Execute the arithmetic, supplier, asset, covered-service, duplicate-identifier, and evidence-path ASK queries.

Run the pure SPARQL workbench queries
type: HowToStep
description: Execute the layer inventory, invoice instance, validation findings, covered-service path, and ASK proof queries.
is part of: How to reproduce the Neo4j-versus-Virtuoso comparison
position: 5
text: Execute the layer inventory, invoice instance, validation findings, covered-service path, and ASK proof queries.

Compare evidence rather than slogans
type: HowToStep
description: Compare returned entities, inferred facts, rule results, provenance paths, and portability while labeling measured and unmeasured claims separately.
is part of: How to reproduce the Neo4j-versus-Virtuoso comparison
position: 6
text: Compare returned entities, inferred facts, rule results, provenance paths, and portability while labeling measured and unmeasured claims separately.

Invoice tax evidence requirement
type: ValidationRule
description: Illustrative rule requiring an explicit tax amount and rate in the invoice evidence used by the proof of concept.
hasEvidence: Illustrative German invoice and tax evidence record
inLayer: LegalLayer

Lindenhof Building A
type: Building
description: Building served by heat pump HP-DE-2048.
has part: Heat pump HP-DE-2048
inLayer: OntologyLayer

Illustrative German invoice and tax evidence record
type: EvidenceDocument
description: Proof-of-concept legal evidence record. It demonstrates source linkage and does not claim to be a complete statement of German law or legal advice.
inLayer: LegalLayer

LegalLayer
type: GraphLayer
description: Legal documents, chunks, obligations, authorities, and regulatory evidence.
has part: Illustrative German invoice and tax evidence record
has part: Invoice tax evidence requirement
is part of: Heat-pump invoice validation proof of concept

Replacement filter
type: InvoiceLineItem
about: Heat pump HP-DE-2048
description: Billable material outside diagnostic coverage
is part of: Invoice RE-2026-0017
inLayer: InvoiceLayer
observedAmount: 180.00

Technician travel
type: InvoiceLineItem
about: Heat pump HP-DE-2048
description: Billable call-out component
is part of: Invoice RE-2026-0017
inLayer: InvoiceLayer
observedAmount: 100.00

What is the article's central architectural claim?
type: Question
accepted answer: Answer 1
has part: Answer 1
is part of: Frequently asked questions

Why is the duplicate invoice only a warning?
type: Question
accepted answer: Answer 10
has part: Answer 10
is part of: Frequently asked questions

Does this collection provide legal advice?
type: Question
accepted answer: Answer 11
has part: Answer 11
is part of: Frequently asked questions

Does the comparison claim every Neo4j system lacks semantics?
type: Question
accepted answer: Answer 12
has part: Answer 12
is part of: Frequently asked questions

What makes an RDF finding auditable?
type: Question
accepted answer: Answer 13
has part: Answer 13
is part of: Frequently asked questions

How does the graph remain layered without duplicating entities?
type: Question
accepted answer: Answer 14
has part: Answer 14
is part of: Frequently asked questions

What does Fixed Entity Architecture do in the source implementation?
type: Question
accepted answer: Answer 2
has part: Answer 2
is part of: Frequently asked questions

Why is Virtuoso treated as a head-on competitor?
type: Question
accepted answer: Answer 3
has part: Answer 3
is part of: Frequently asked questions

What is KG-only mode in this collection?
type: Question
accepted answer: Answer 4
has part: Answer 4
is part of: Frequently asked questions

Why remove vector-function SPARQL from this edition?
type: Question
accepted answer: Answer 5
has part: Answer 5
is part of: Frequently asked questions

Does the proof require Virtuoso vector functions?
type: Question
accepted answer: Answer 6
has part: Answer 6
is part of: Frequently asked questions

Was the pure SPARQL proof executed during generation?
type: Question
accepted answer: Answer 7
has part: Answer 7
is part of: Frequently asked questions

Which parts were executed?
type: Question
accepted answer: Answer 8
has part: Answer 8
is part of: Frequently asked questions

What invoice defect does the proof of concept find?
type: Question
accepted answer: Answer 9
has part: Answer 9
is part of: Frequently asked questions

Invoice arithmetic rule
type: ValidationRule
description: Line items sum to EUR 400.00; tax is EUR 76.00; total due is EUR 476.00.
inLayer: RulesLayer

Service call-out ceiling rule
type: ValidationRule
description: The total invoice amount of EUR 476.00 exceeds the illustrative EUR 450.00 call-out ceiling.
inLayer: RulesLayer

Covered-service billing rule
type: ValidationRule
description: The diagnostic line is billed even though the annual service contract says that diagnostic visit is covered.
inLayer: RulesLayer

Duplicate invoice identifier rule
type: ValidationRule
description: A prior invoice record uses the same supplier invoice identifier.
inLayer: RulesLayer

Heat-pump warranty
type: EvidenceDocument
about: Heat pump HP-DE-2048
description: Illustrative warranty active from installation through 2027-09-14 and covering qualifying diagnostic work.
valid from: 2025-09-15
valid through: 2027-09-14
inLayer: ContractsLayer

Diagnostic inspection
type: InvoiceLineItem
about: Heat pump HP-DE-2048
description: Covered by the annual service contract
is part of: Invoice RE-2026-0017
inLayer: InvoiceLayer
observedAmount: 120.00

Power of Layered Knowledge Graphs Applied to Real Estate Management: GraphRAG Re-born
type: Article
author: Irina Adamchic, PhD
date published: 2026-08-02

ContractsLayer
type: GraphLayer
description: Installation, warranty, and service-contract evidence.
has part: Heat-pump installation contract
has part: Installation record for HP-DE-2048
has part: Annual heat-pump service contract
has part: Heat-pump warranty
is part of: Heat-pump invoice validation proof of concept

Annual heat-pump service contract
type: EvidenceDocument
about: Heat pump HP-DE-2048
description: Illustrative service agreement covering one diagnostic visit per contract year and imposing a EUR 450 call-out ceiling.
provider: ThermoHaus Service
expectedAmount: 450.00
inLayer: ContractsLayer

ThermoHaus Service
type: Organization
description: Illustrative contractor named consistently across installation, contract, service, and invoice evidence.

InvoiceLayer
type: GraphLayer
description: Invoices, line items, tax, totals, and supplier evidence.
has part: Invoice RE-2026-0017
has part: Diagnostic inspection
has part: Replacement filter
has part: Technician travel
has part: Prior invoice record RE-2026-0017
is part of: Heat-pump invoice validation proof of concept

Heat-pump invoice validation proof of concept
type: CreativeWork
description: A representative invoice is checked against installation data, equipment identity, warranty coverage, a service contract, contractor identity, arithmetic, tax, supporting evidence, and a call-out price ceiling.
has part: ContractsLayer
has part: InvoiceLayer
has part: LegalLayer
has part: OntologyLayer
has part: RulesLayer
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
position: 3
text: A representative invoice is checked against installation data, equipment identity, warranty coverage, a service contract, contractor identity, arithmetic, tax, supporting evidence, and a call-out price ceiling.

How to reproduce the Neo4j-versus-Virtuoso comparison
type: HowTo
description: Six-step procedure for loading, querying, validating, and inspecting the pure SPARQL proof of concept.
has part: Load the companion Turtle graph
has part: Inspect the five source layers
has part: Run KG-only semantic selection
has part: Run the validation ASK queries
has part: Run the pure SPARQL workbench queries
has part: Compare evidence rather than slogans
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
step: Load the companion Turtle graph
step: Inspect the five source layers
step: Run KG-only semantic selection
step: Run the validation ASK queries
step: Run the pure SPARQL workbench queries
step: Compare evidence rather than slogans

Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
type: AnalysisNewsArticle
about: Neo4j Linked Property Graph architecture
about: Virtuoso RDF knowledge-graph architecture
abstract: One invoice-validation problem is modeled through the article's Neo4j property-graph design and through Virtuoso's RDF-native semantics, inference, provenance, and standards-based SPARQL query surface.
accountable person: this
article body: The comparison holds the real-estate evidence constant while changing the graph platform. Neo4j uses Fixed Entity Architecture, labels, vector indexes, Graph Builder, and Cypher. Virtuoso uses RDF IRIs, ontology axioms, graph patterns, inference, provenance, and pure SPARQL over generated ontology instances.
author: kg-generator skill
date created: 2026-08-10
description: Source-grounded notes about Irina Adamchic's article, paired with an executable RDF proof of concept that compares Neo4j GraphRAG with a pure SPARQL Virtuoso/RDF showcase.
has part: One problem, two competing graph architectures
has part: Frequently asked questions
has part: Layered graph comparison glossary
has part: How to reproduce the Neo4j-versus-Virtuoso comparison
has part: Layered Real-Estate Graph Comparison Ontology
has part: Heat-pump invoice validation proof of concept
has part: Reproducible query and validation recipes
has part: Executed pure SPARQL evidence
has part: Schema selection: vector GraphRAG versus pure SPARQL
has part: What the source article builds
is based on: Power of Layered Knowledge Graphs Applied to Real Estate Management: GraphRAG Re-born
was generated by: data-twingler skill
was generated by: kg-generator skill
was generated by: rdf-infographic-skill
was generated by: Codex

Heat pump HP-DE-2048
type: HeatPump
date installed: 2025-09-15
description: Installed heat-pump asset referenced by the contract, warranty, service record, and invoice.
serial number: HP-DE-2048
inLayer: OntologyLayer

OpenLink Virtuoso
type: SoftwareApplication
description: Multi-model database and RDF quad store used by the RDF-based competing design.

Layered graph comparison glossary
type: DefinedTermSet
description: Terms used across the Neo4j and Virtuoso implementations.
has defined term: Evidence path
has defined term: Fixed Entity Architecture
has defined term: GraphRAG
has defined term: RDF inference
has defined term: KG-only retrieval
has defined term: Linked Property Graph
has defined term: Named graph
has defined term: OntologyLayer
has defined term: Provenance
has defined term: Pure SPARQL proof
has defined term: Resource Description Framework
has defined term: Shapes Constraint Language
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso

Reproducible query and validation recipes
type: CreativeWork
description: Named code resources preserve the source Cypher and provide RDF, SPARQL, and Virtuoso query recipes for reproducing the comparison.
has part: ASK Arithmetic
has part: ASK Asset
has part: ASK CoveredDiagnostic violation
has part: ASK Duplicate
has part: ASK evidence path
has part: ASK Supplier
has part: Pure SPARQL covered-service evidence path
has part: Pure SPARQL invoice instance details
has part: Pure SPARQL layer inventory
has part: Pure SPARQL validation findings
has part: Source Neo4j GraphRAG ontology pre-filter
has part: Virtuoso KG-only ontology-slice query
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
position: 6
text: Named code resources preserve the source Cypher and provide RDF, SPARQL, and Virtuoso query recipes for reproducing the comparison.

Neo4j Linked Property Graph architecture
type: GraphArchitecture
description: Source-described architecture using Neo4j Community Edition, Fixed Entity Architecture, labeled layers, Graph Builder, vector indexes, Cypher, APOC, and Neo4j MCP.
instrument: Neo4j
is based on: Power of Layered Knowledge Graphs Applied to Real Estate Management: GraphRAG Re-born
supportsCapability: Cypher graph querying
supportsCapability: Fixed Entity Architecture
supportsCapability: Neo4j vector index

Frequently asked questions
type: FAQPage
description: Questions covering the article, the controlled comparison, and the limits of the proof of concept.
has part: What is the article's central architectural claim?
has part: Why is the duplicate invoice only a warning?
has part: Does this collection provide legal advice?
has part: Does the comparison claim every Neo4j system lacks semantics?
has part: What makes an RDF finding auditable?
has part: How does the graph remain layered without duplicating entities?
has part: What does Fixed Entity Architecture do in the source implementation?
has part: Why is Virtuoso treated as a head-on competitor?
has part: What is KG-only mode in this collection?
has part: Why remove vector-function SPARQL from this edition?
has part: Does the proof require Virtuoso vector functions?
has part: Was the pure SPARQL proof executed during generation?
has part: Which parts were executed?
has part: What invoice defect does the proof of concept find?
is part of: Notes on Layered Real-Estate Knowledge Graphs: Neo4j and Virtuoso
main entity: What is the article's central architectural claim?
main entity: Why is the duplicate invoice only a warning?
main entity: Does this collection provide legal advice?
main entity: Does the comparison claim every Neo4j system lacks semantics?
main entity: What makes an RDF finding auditable?
main entity: How does the graph remain layered without duplicating entities?
main entity: What does Fixed Entity Architecture do in the source implementation?
main entity: Why is Virtuoso treated as a head-on competitor?
main entity: What is KG-only mode in this collection?
main entity: Why remove vector-function SPARQL from this edition?
main entity: Does the proof require Virtuoso vector functions?
main entity: Was the pure SPARQL proof executed during generation?
main entity: Which parts were executed?
main entity: What invoice defect does the proof of concept find?

Virtuoso RDF knowledge-graph architecture
type: GraphArchitecture
description: RDF-native competitor architecture using HTTP IRIs, RDF/OWL semantics, SPARQL, provenance, and inference-oriented graph patterns.
has part: data-twingler KG-only mode
instrument: OpenLink Virtuoso
is based on: Power of Layered Knowledge Graphs Applied to Real Estate Management: GraphRAG Re-born
supportsCapability: PROV-O evidence lineage
supportsCapability: RDF HTTP IRI identity
supportsCapability: RDF inference
supportsCapability: SPARQL graph querying

Invoice RE-2026-0017
type: Invoice
about: Heat pump HP-DE-2048
customer: Lindenhof Property
date issued: 2026-07-28
description: Illustrative heat-pump service invoice evaluated by every proof-of-concept rule.
has part: Diagnostic inspection
has part: Replacement filter
has part: Technician travel
provider: ThermoHaus Service
tax: 76.00
total payment due: 476.00
inLayer: InvoiceLayer
observedAmount: 476.00

OntologyLayer
type: GraphLayer
description: Stable domain vocabulary and imported ontology concepts.
has part: Akoma Ntoso (OASIS)
has part: Brick Schema
has part: Building
has part: Custom ontology
has part: FIBO (EDM Council)
has part: Heat pump
has part: Invoice
has part: Legal requirement
has part: LKIF-Core
has part: P2P-O (DFKI)
has part: RealEstateCore
has part: Service contract
has part: Warranty
is part of: Heat-pump invoice validation proof of concept

RulesLayer
type: GraphLayer
description: Deterministic validation rules and named findings.
has part: PASS: Invoice arithmetic rule
has part: PASS: Supplier identity rule
has part: PASS: Equipment identity rule
has part: PASS: Warranty-period rule
has part: FAIL: Covered-service billing rule
has part: WARNING: Duplicate invoice identifier rule
has part: WARNING: Service call-out ceiling rule
has part: PASS: Tax evidence rule
has part: Invoice arithmetic rule
has part: Equipment identity rule
has part: Service call-out ceiling rule
has part: Covered-service billing rule
has part: Duplicate invoice identifier rule
has part: Supplier identity rule
has part: Tax evidence rule
has part: Warranty-period rule
is part of: Heat-pump invoice validation proof of concept

Layered Real-Estate Graph Comparison Ontology
type: Ontology
description: Lightweight ontology for comparing Neo4j and Virtuoso implementations and for executing the heat-pump invoice validation proof of concept.
comment: Defines architecture, layer, retrieval, rule, evidence, and validation concepts used by the proof of concept.