Description-Logic Knowledge Representation System Specification
Working Version (Draft):
Description-Logic Knowledge Representation System Specification
from the KRSS Group of the ARPA Knowledge Sharing Effort
Peter F. Patel-Schneider, co-chair
Bill Swartout, co-chair
1 November 1993
This is the KRSS group specification for description-logic-based KR
systems. It describes the required behavior for compliant KR systems.
This report is not an overview of description logics, nor is it a
rationale for using description logics in knowledge representation.
The description logic in this specification is based closely on the
description logic defined by researchers at DFKI. However, it
includes several other features, notably role closures and rules.
A knowledge base in this specification is a sequence of statements.
The semantics of non-rule, non-closure statements is similar to that
in the DFKI proposal. The semantics of role closures is determined by
replacing them, in sequence, with the best derivable role maximum or
the derivable set of fillers. Rules are treated as epistemic
statements, in line with their treatment by Donini et. al.
Compliant implementations are required to parse the entire language,
but may replace constructs that they cannot reason about with the
closest approximation that they can handle. Compliant implementations
are required to be complete on a subset of the logic, selected for its
easy, but non-trivial, inferences.
A full copy of this document is available in