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Glossary

Knowledge Base

An independent producer and/or consumer of information.

Knowledge Network

A set of Knowledge Bases that securely exchange knowledge about a clearly defined domain.

Knowledge Engine Runtime

A single instance that is part of a Knowledge Network. It takes care of the communication between one (or more!) Knowledge Base(s) and the rest of the Knowledge Network.

Knowledge Directory

A registry that keeps track of all Knowledge Bases (as represented by Smart Connectors), and specifically their knowledge needs and desires.

Smart Connector

An entity (currently in the form of a Java object) that enables a Knowledge Base to connect to a Knowledge Network and exchange knowledge.

Knowledge Interaction

A specification of knowledge that a Knowledge Base processes. A Knowledge Interaction is always one of the following four types: ASK, ANSWER, POST, REACT.

ASK

A request for knowledge.

ANSWER

Answer to a request for knowledge

POST

A publication of knowledge.

REACT

Reaction to the publication of knowledge

Graph Pattern

A set of triples, separated by a dot (.), that describe the Knowledge that is processed with a Knowledge Interaction. Each triple consists of a subject, predicate, and object. Each of these can be either a variable (using a question mark ?var prefix), a URI (using the <https://...>) or a literal (using quotes "hello")

On the Expressibility of Graph Patterns

Currently, the Knowledge Engine only supports Basic Graph Patterns. It does not yet support features such as the FILTER from SPARQL.

Binding Set

A result of a Knowledge Interaction can have more than 1 match. These matches are collected in a BindingSet, which is simply a set of bindings.

Binding

Describes a 'match' of a graph pattern. Essentially it maps (free) variables in a graph pattern to actual values. Variables can be identified in a graph pattern as they are always prefixed with ?.

Two important things should be noted:

  1. The keys of the bindings MUST correspond to the variable names in the graph pattern, and they must be complete (all variables must have a value bound to them). (This last restriction does not apply to the bindings given with ASK requests; they can be partial of even empty.)
  2. The values of the bindings MUST be valid IRIs (https://www.w3.org/TR/turtle/#sec-iri) (for now without prefixes, so full IRIs) or valid literals (https://www.w3.org/TR/turtle/#literals).