The Semantics of Datalog for the Evidential Tool Bus

SRI Authors: Natarajan Shankar

Abstract

The Evidential Tool Bus (ETB) is a distributed framework for tool integration for the purpose of building and maintaining assurance cases. ETB employs Datalog as a metalanguage both for defining workflows and representing arguments. The application of Datalog in ETB differs in some significant ways from its use as a database query language. For example, in ETB Datalog predicates can be tied to external tool invocations. The operational treatment of such external calls is more expressive than the use of built-in predicates in Datalog. We outline the semantic characteristics of the variant of Datalog used in ETB and describe an abstract machine for evaluating Datalog queries.

Share this