Semantic reasoner

"Reasoner" redirects here. For other uses, see Reasoner (disambiguation).

A semantic reasoner, reasoning engine, rules engine, or simply a reasoner, is a piece of software able to infer logical consequences from a set of asserted facts or axioms. The notion of a semantic reasoner generalizes that of an inference engine, by providing a richer set of mechanisms to work with. The inference rules are commonly specified by means of an ontology language, and often a description language. Many reasoners use first-order predicate logic to perform reasoning; inference commonly proceeds by forward chaining and backward chaining. There are also examples of probabilistic reasoners, including Pei Wang's non-axiomatic reasoning system, Novamente's probabilistic logic network, which tip their hat to reasoning Bayesian networks, and Pronto [1] - probabilistic Description logic reasoner.

[edit] Semantic reasoners

Existing semantic reasoners:

Bossam (software), an RETE-based rule engine with native supports for reasoning over OWL ontologies, SWRL ontologies, and RuleML rules.
Hoolet, reasons over OWL-DL ontologies by translating them to full first-order logic and then applying a first-order theorem prover. [2]
Pellet, an open-source Java OWL DL reasoner. [3]
SHER, a scalable Pellet-backed OWL DL reasoner. [4]
KAON2 is an infrastructure for managing OWL-DL, SWRL, and F-Logic ontologies.
RACER system, a semantic web reasoning system and information repository
Jena (framework), an open source semantic web framework for Java which includes a number of different semantic reasoning modules.
FaCT, a description logic (DL) classifier. [5]
FaCT++, the new generation of FaCT OWL-DL reasoner. [6]
SweetRules, an integrated set of tools for Semantic web rules and ontologies. [7]
OWLIM, a high-performance semantic repository developed in Java and available in two versions: free SwiftOWLIM and commercial BigOWLIM [8]. Supports a subset of OWL-Lite semantics, which can be configured through rule-set definition and selection. [9].

	Bossam	Hoolet	Pellet	KAON2	RacerPro	Jena	FaCT	FaCT++	SweetRules	OWLIM
OWL-DL Entailment	?	Yes	Yes	Yes	Yes	No complete reasoner included with standard distribution	Yes	Yes	No	No
Supported expressivity for reasoning	?	?	SROIQ(D)	SHIQ(D)	?	varies by reasoner (incomplete for nontrivial description logics)	SHIQ	SROIQ(D)	?	R-entailment
Reasoning algorithm	Rule-based	First-order prover	Tableau	Resolution & Datalog	Tableau	Rule-based	Tableau	Tableau	Rule-based	Rule-based
Consistency checking	?	Yes	Yes	?	Yes	Incomplete for OWL DL	Yes	Yes	No	No
DIG Support	No	No	Yes	Yes	Yes	Yes	Yes	Yes	No	No
Rule Support	Yes (SWRL & own rule format)	Yes (SWRL)	Yes (SWRL -- DL Safe Rules)	Yes (SWRL -- DL Safe Rules)	Yes (SWRL -- not fully support SWRL)	Yes (Own rule format)	No	No	Yes (SWRL, RuleML, Jess)	Yes (Own format)
Version	0.9b45	?	2.0 RC5	?	1.9.2	2.5.4	?	1.1.8	2.1	2.x/3.x
Licencing	Free/ closed-source	Free/ open-source	Free/ open-source & Non-Free/ closed-source	Free/ closed-source	Non-Free/ closed-source	Free/ open-source	Free/ open-source	Free/ open-source	Free/ open-source	Free/ open-source & Non-Free/ closed-source