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The '''superposition calculus''' is a calculus for [[automated theorem proving|reasoning]] in equational [[first-order logic]]. It has been developed in the early 1990s and combines concepts from [[first-order resolution]] with ordering-based equality handling as developed in the context of (unfailing) [[Knuth-Bendix completion algorithm|Knuth-Bendix completion]]. It can be seen as a generalization of either resolution (to equational logic) or unfailing completion (to full clausal logic). As most first-order calculi, superposition tries to show the ''unsatisfiability'' of a set of first-order [[clauses]], i.e. it performs proofs by [[refutation]]. Superposition is refutation-complete — given unlimited resources and a ''fair'' derivation strategy, every [[unsatisfiable (logic)|unsatisfiable]] clause set can eventually be proved to be unsatisfiable.
The '''superposition calculus''' is a calculus for [[automated theorem proving|reasoning]] in equational [[first-order logic]]. It has been developed in the early 1990s and combines concepts from [[first-order resolution]] with ordering-based equality handling as developed in the context of (unfailing) [[Knuth-Bendix completion algorithm|Knuth-Bendix completion]]. It can be seen as a generalization of either resolution (to equational logic) or unfailing completion (to full clausal logic). As most first-order calculi, superposition tries to show the ''unsatisfiability'' of a set of first-order [[clauses]], i.e. it performs proofs by [[refutation]]. Superposition is refutation-complete — given unlimited resources and a ''fair'' derivation strategy, every unsatisfiable (logic)|unsatisfiable clause set can eventually be proved to be unsatisfiable.


As of 2007, most of the (state-of-the-art) [[Automated theorem prover|theorem prover]]s for [[first-order logic]] are based on superposition (e.g. the [[E equational theorem prover]]), although only a few implement the pure calculus.
As of 2007, most of the (state-of-the-art) [[Automated theorem prover|theorem prover]]s for [[first-order logic]] are based on superposition (e.g. the [[E equational theorem prover]]), although only a few implement the pure calculus.
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* [[SPASS theorem prover|SPASS]]
* [[SPASS theorem prover|SPASS]]
* [[Vampire theorem prover|Vampire]]
* [[Vampire theorem prover|Vampire]]
* [[Waldmeister theorem prover|Waldmeister]]
* Waldmeister theorem prover|Waldmeister
* [[Ayane theorem prover|Ayane]] at [http://code.google.com/p/ayane/ Google Code ]
* Ayane theorem prover|Ayane at [http://code.google.com/p/ayane/ Google Code ]


== References ==
== References ==

Revision as of 02:38, 1 February 2013

The superposition calculus is a calculus for reasoning in equational first-order logic. It has been developed in the early 1990s and combines concepts from first-order resolution with ordering-based equality handling as developed in the context of (unfailing) Knuth-Bendix completion. It can be seen as a generalization of either resolution (to equational logic) or unfailing completion (to full clausal logic). As most first-order calculi, superposition tries to show the unsatisfiability of a set of first-order clauses, i.e. it performs proofs by refutation. Superposition is refutation-complete — given unlimited resources and a fair derivation strategy, every unsatisfiable (logic)|unsatisfiable clause set can eventually be proved to be unsatisfiable.

As of 2007, most of the (state-of-the-art) theorem provers for first-order logic are based on superposition (e.g. the E equational theorem prover), although only a few implement the pure calculus.

Implementations

References

  • Rewrite-Based Equational Theorem Proving with Selection and Simplification, Leo Bachmair and Harald Ganzinger, Journal of Logic and Computation 3(4), 1994.
  • Paramodulation-Based Theorem Proving, Robert Nieuwenhuis and Alberto Rubio, Handbook of Automated Reasoning I(7), Elsevier Science and MIT Press, 2001.