ISO/IEC 21838-4:2023

Overview

ISO/IEC 21838-4:2023 - TUpper defines TUpper, a top-level ontology (TLO) that is conformant with the requirements in ISO/IEC 21838-1. TUpper is published with three complementary artifacts: a natural-language specification (TUpper‑Terms), an OWL 2 formalization (TUpper‑OWL) and a Common Logic (CL) axiomatization (TUpper‑CL). The standard documents the ontology signature (classes and relations), OWL/CL axiomatizations, modular structure, conformity evidence to ISO/IEC 21838-1, and the methodology for creating domain ontologies that conform to TUpper.

Key topics and requirements

• Conformance to ISO/IEC 21838-1: TUpper documents how its elements satisfy the requirements for top-level ontologies in the Part 1 standard.
• Multi‑notation delivery: Natural language, OWL 2 and Common Logic representations are provided to support human understanding, OWL-based integration/reasoning, and a formal CL semantics.
• Modularity (sideways approach): TUpper is a modular TLO composed of modules (e.g., time, process, space, mereotopology) derived from existing ISO ontologies rather than a single monolithic taxonomy.
• Scope inclusions:
  • Definitions of classes and relations in the TUpper signature
  • Axiomatizations in OWL 2 and CL
  • Documentation of conformity and methodology for domain‑ontology conformance
• Scope exclusions:
  • Specification of ontology languages (RDF, OWL, CL)
  • Methods for reasoning with ontologies
  • Translators between ontology notations
• Conformance rule for domain ontologies: A domain ontology conforms to TUpper iff its axioms (in the same CL dialect) are a consistent extension of the TUpper axiomatization.

Applications and users

TUpper is designed to support practical tasks in semantic technologies and information systems:

• Ontology design & integration: Provides reusable top-level concepts to harmonize domain ontologies and enable semantic integration across heterogeneous systems.
• Automated reasoning: OWL 2 formalization allows use with OWL reasoners for classification and consistency checks; CL axiomatization captures intended semantics.
• Standards alignment: Enables applications that must interoperate with multiple ISO-standard ontologies. Primary users:
• Ontology engineers and knowledge engineers
• Semantic web and linked-data developers
• Data architects, system integrators, and AI practitioners working on semantic interoperability
• Standards organizations and domain modelers

Related standards

• ISO/IEC 21838-1:2021 - Top-level ontologies (requirements)
• ISO/IEC 24707 - Common Logic (CL) framework
• ISO 18629 (PSL modules), ISO 19107, ISO/TS 19150-1, ISO/IEC 80000 - sources of modules incorporated in TUpper

Keywords: ISO/IEC 21838-4:2023, TUpper, top-level ontology, TLO, OWL 2, Common Logic, ontology integration, semantic integration, modular ontology, ISO top-level ontology.