Dictionary Definition

reasoner n : someone who reasons logically [syn: ratiocinator]

User Contributed Dictionary

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 probalistic reasoners, including Pei Wang's non-axiomatic reasoning system, Novamente's probabilistic logic network, which tip their hat to reasoning Bayesian networks, and Pronto http://pellet.owldl.com/pronto - probabilistic Description logic reasoner.

Existing semantic reasoners:

Bossam, an RETE-based rule engine with native supports for reasoning over OWL ontologies, SWRL ontologies, and RuleML rules.
Hoolet, an implementation of an OWL-DL reasoner. http://owl.man.ac.uk/hoolet/
Pellet, an open-source Java OWL DL reasoner. http://pellet.owldl.com/
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.
FaCT, a description logic (DL) classifier. http://www.cs.man.ac.uk/~horrocks/FaCT/
FaCT++, the new generation of FaCT OWL-DL reasoner. http://owl.man.ac.uk/factplusplus/
SweetRules, an integrated set of tools for Semantic web rules and ontologies. http://sweetrules.projects.semwebcentral.org/

reasoner in Spanish: Web semántica

reasoner in Italian: Ragionatore automatico