NBN ISO/IEC 24707:2021

This document specifies a family of logic languages designed for use in the representation and
interchange of information and data among disparate computer systems.
The following features are essential to the design of this document.
— Languages in the family have declarative semantics. It is possible to understand the meaning of
expressions in these languages without appeal to an interpreter for manipulating those expressions.
— Languages in the family are logically comprehensive – at its most general, they provide for the
expression of arbitrary first-order logical sentences.
— Languages in the family are translatable by a semantics-preserving transformation to a common
XML-based syntax, facilitating interchange of information among heterogeneous computer systems.
The following are within the scope of this document:
— representation of information in ontologies and knowledge bases
— specification of expressions that are the input or output of inference engines
— formal interpretations of the symbols in the language.
The following are outside the scope of this document:
— specification of proof theory or inference rules
— specification of translators between the notations of heterogeneous computer systems
— computer-based operational methods of providing relationships between symbols in the logical
“universe of discourse” and individuals in the “real world”.
This document describes Common Logic’s syntax and semantics.
This document defines an abstract syntax and an associated model-theoretic semantics for a specific
extension of first-order logic. The intent is that the content of any system using first-order logic can
be represented in this document. The purpose is to facilitate interchange of first-order logic-based
information between systems.
Issues relating to computability using this document (including efficiency, optimization, etc.) are not
addressed.