ISO/IEC 21838 Top-Level Ontologies (TLO)
- Part 1 of this standard was published by ISO in August 2021. It specifies the requirements' for being a top-level ontology.
- See https://www.iso.org/standard/71954.html
- For those working on standards this document is freely available at this ISO site
ISO/IEC 21838-2 Basic Formal Ontology (BFO)
- This is Part 2 of the standard; it standardizes BFO 2020 as a top-level ontology conforming to Part 1. It was published by ISO in November, 2021, and is available at
- For those working on standards this document is freely available at this ISO site.
The entire content of BFO 2020 is freely available here:
- This includes:
- bfo-2020-terms.xlsx (terms and relational expressions with definitions and examples)
- bfo-2020-iris.xlsx (table of IRIs for all classes and relations in BFO-2020-CL, the Common Logic axiomatization of BFO, and including all classes and relations in BFO-2020-OWL)
- bfo-2020-relations-table.xlsx (table of all relations in BFO-2020-CL, including all inverses, reverses*, and all binary variants used in BFO-2020-OWL)
- The owl folder includes
- bfo-2020.owl – OWL in rdf/xml format
- bfo-2020.ofn – OWL in functional syntax
- bfo-2020-labeled.ofn – OWL in functional syntax with labels instead of IRIs
- bfo-2020-without-some-all-times.owl – as for 5. but without the binaryized relations
- The common-logic folder provides the complete set of modules in the CL formalization of BFO-2020 together with
- temporalized-relations.cl, which contains CL definitions of the binary at-all-times/some-time relations used in bfo-2020-owl.
- The pdf folder provides the complete set of modules in the CL axiomatization of BFO 2020 in traditional first-order logic (FOL) syntax.
- The prover9 folder provides the same set of modules in prover 9 format, together with, together with
- temporalized-relations.p9, which provdes the content of temporalized-relations.cl in prover9 format
- The model folder provides three versions of the model used to prove consistency of the CL formalization, in prover 9, CLIF, and clausetester formats respectivly.
The most current version of these files will be at https://github.com/BFO-ontology/BFO-2020.
[*] The concept of reverse relation is only relevant for at-all-time relations. See reverse-vs-inverse for an explanation.
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