Concept
LOOM (ontology)
Overview
Loom is a knowledge representation language developed by researchers in the artificial intelligence research group at the University of Southern California's Information Sciences Institute. The leader of the Loom project and primary architect for Loom was Robert MacGregor. The research was primarily sponsored by the Defense Advanced Research Projects Agency (DARPA).
Loom is a frame-based language in the tradition of KL-ONE. As with KL-ONE, Loom has a formal semantics that maps declarations in Loom to statements in set theory and first-order logic. This formal semantics enables a type of theorem prover engine called a classifier. The classifier can analyze Loom models (known as ontologies) and deduce various things about the model. For example, the classifier can discover new classes or change the subclass/superclass relations in the model. The classifier can also detect inconsistencies in the model declaration. This is a very powerful and fairly unusual capability in that it is capable of doing analysis at the ontology level, the level of declarations rather than at the implementation level as most inference engines do.
The Loom project's goal is the development and fielding of advanced tools for knowledge representation and reasoning in artificial intelligence. Specifically to enable code to be generated from provably valid domain models.
Loom is a language and environment for constructing intelligent applications. At its heart is a knowledge representation and reasoning system that combines a Frame-based language with an automatic classifier engine. Declarative knowledge in Loom consists of definitions, rules, facts, and default rules. A deductive engine called a classifier utilizes forward chaining, semantic unification, and object-oriented truth maintenance technologies in order to compile the declarative knowledge into a network designed to efficiently support on-line deductive query processing.
The Loom system implements a logic-based pattern matcher that drives a production rule facility and a pattern-directed method dispatching facility that supports the definition of object-oriented methods. The high degree of integration between Loom's declarative and procedural components permits programmers to utilize logic programming, production rule, and object-oriented programming paradigms in a single application. Loom can also be used as a deductive layer that overlays an ordinary CLOS (Common Lisp Object System) network. In this mode, users can obtain many of the benefits of using Loom without impacting the function or performance of their CLOS-based applications.
Loom has recently been succeeded by PowerLoom.
Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).
In the original texts
Passages from public-domain books where LOOM (ontology) is discussed.
But we have to remember that we have got to deal with hand-spun yarn which is not likely to have a good test for some time to come. It is therefore that the old loom is the safest and surest weaving instrument to go on with for the present. _Y. I.--25th Aug. 1921._
Mahatma Gandhi, The Wheel of Fortune
names the idea; a chapter is titled for it; states what it is; opens on it
And these poor hand-loom weavers, first to suffer from every crisis, and last to be relieved from it, must serve the bourgeoisie as a handle in meeting attacks upon the factory system. "See," cries the bourgeois, triumphantly, "see how these poor creatures must famish, while the mill operatives are thriving, and _then_ judge the factory {140} system!" As though it were not precisely the factory system and the…
Friedrich Engels, The Condition of the Working-Class in England in 1844 with a Preface written in 1892
names the idea; opens on it
The chief business of the logician is to classify arguments; for all testing clearly depends on classification. The classes of the logicians are defined by certain typical forms called syllogisms. For example, the syllogism called _Barbara_ is as follows: S is M; M is P: Hence, S is P. Or, to put words for letters— Enoch and Elijah were men; all men die: Hence, Enoch and Elijah must have died.
Charles S. Peirce, Chance, Love, and Logic
states what it is
It is easy to see why an objective looms so large and why emotional surge and stress gather about it and lift it high above the floor of consciousness. The objective is (or is taken to be) the key to the situation. If we can attain it, lay hold of it, the trick is turned. It is like the piece of paper which carries the reprieve a condemned man waits for. Issues of life hang upon it. The desired object is in no sense…
John Dewey, Human Nature and Conduct
opens on it; names the idea
Any such select set is called the set of postulates, or premises, from which the reasoning proceeds. The reasoning is nothing else than the exhibition of the whole pattern of general conditions involved in the pattern derived from the selected postulates.
Alfred North Whitehead, Science and the modern world
states what it is
Related ideas
- First-order logic
- Artificial intelligence
- Knowledge representation and reasoning
- Declarative knowledge
- Set theory
- KL-ONE
Place in the tradition
Part of Description logic.