What is OWL?

OWL (Web Ontology Language) is a critical component in how FOLIO represents complex legal concepts and relationships across multiple standards. It provides the expressive power needed to capture the nuances of legal information.

What is OWL?

OWL (Web Ontology Language) is a family of knowledge representation languages for authoring ontologies. Developed as a vocabulary extension of RDF, OWL provides a rich set of constructs to describe complex models with formal semantics.

OWL goes beyond simpler standards like RDFS and SKOS by offering more expressive capabilities for defining:

  • Classes and their relationships
  • Properties and their characteristics
  • Restrictions on how properties can be used
  • Logical axioms and rules

OWL comes in several “flavors” or profiles (OWL 2 DL, OWL 2 RL, OWL 2 QL, OWL 2 EL) that balance expressivity with computational efficiency for different use cases.

How FOLIO Uses OWL

FOLIO leverages OWL in several critical ways:

  1. Class Definitions: FOLIO uses OWL to define its extensive taxonomy of legal concepts (like Contract, Court, Jurisdiction) as classes.

  2. Property Relationships: OWL properties describe how concepts relate to each other, such as:

    • Object properties: relationships between entities (e.g., “issuedBy” connecting a Judgment to a Court)
    • Data properties: relationships between entities and data values (e.g., “effectiveDate” for a Contract)

  3. Logical Constraints: OWL allows FOLIO to express constraints like:

    • A “Federal Court” must be part of exactly one national jurisdiction
    • A “Settlement Agreement” must have at least two parties

  4. Class Hierarchies: OWL supports sophisticated class hierarchies, allowing FOLIO to represent the complex taxonomies needed for legal information.

Example: OWL in FOLIO

Here’s a simplified example of how FOLIO might represent a legal concept using OWL (in Turtle syntax):

@prefix folio: <https://folio.openlegalstandard.org/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .

folio:Contract rdf:type owl:Class ;
    rdfs:label "Contract" ;
    rdfs:subClassOf folio:LegalDocument ;
    owl:disjointWith folio:Statute .

folio:hasParty rdf:type owl:ObjectProperty ;
    rdfs:domain folio:Contract ;
    rdfs:range folio:LegalEntity ;
    rdfs:label "has party" .

folio:BilateralContract rdf:type owl:Class ;
    rdfs:subClassOf folio:Contract ;
    rdfs:subClassOf [
        rdf:type owl:Restriction ;
        owl:onProperty folio:hasParty ;
        owl:minCardinality "2"^^xsd:nonNegativeInteger
    ] .

This example shows a Contract class with a property for parties, and a BilateralContract that must have at least two parties.

OWL provides several key benefits for representing legal standards in FOLIO:

  1. Formal Semantics: Reduces ambiguity and enables automated reasoning about legal concepts.
  2. Expressive Power: Captures complex relationships and constraints in legal domains.
  3. Integration Capabilities: Facilitates the integration of multiple standards and knowledge bases.
  4. Extensibility: Allows new concepts to be defined in terms of existing ones.
  5. Validation: Enables checking for consistency and coherence across complex models.

How OWL Supports FOLIO’s Modular and Federated Design

OWL is particularly well-suited to FOLIO’s approach to legal standards:

  • Modular Design: OWL ontologies can be divided into modules that can be developed and maintained independently.
  • Ontology Imports: One OWL ontology can import another, allowing for composition of modular ontologies.
  • Distributed Development: Different organizations can develop their own extensions while remaining compatible with core FOLIO ontologies.
  • Bridging Standards: OWL’s expressive capabilities allow mapping between concepts in different standards.

Consider how FOLIO might use OWL to connect standards from different jurisdictions:

# US UCC concept
folio:UCC-2-206 rdf:type owl:Class ;
    rdfs:label "UCC § 2-206: Offer and Acceptance in Formation of Contract" .

# CISG concept (international treaty)
folio:CISG-Article-14 rdf:type owl:Class ;
    rdfs:label "CISG Article 14: Offer Definition" .

# Relationship between concepts in different standards
folio:UCC-2-206 owl:equivalentClass [
    owl:intersectionOf (
        folio:CISG-Article-14
        folio:CISG-Article-18
    )
] .

This example shows how OWL can express that concepts from the US Uniform Commercial Code relate to concepts from the UN Convention on Contracts for the International Sale of Goods.

Explore the FOLIO Taxonomy

Browse the complete FOLIO taxonomy through our interactive browser.

Explore Taxonomy →

Further Reading

To continue exploring the technologies that power FOLIO: