Tau: A Web-Deployed Hybrid Prover for First-Order Logic with Identity, with Optional Inductive Proof

We outline Tau, a practical and extensible hybrid theorem prover for first-order predicate calculus with identity. Tau is flexible and user-configurable, accepts the KIF Language, is implemented in Java, and has multiple user interfaces. Tau combines rule-based problem rewriting with Model Elimination, uses Brand’s Modification Method to implement identity, and accepts user-configurable heuristic search to speed the search for proofs. Tau optionally implements mathematical induction. Formulas are input and output in KIF or infix FOPC, and other external forms can be added. Tau can be operated from a Web interface or from a command-line interface. Tau is implemented entirely in Java and can run on any system for which a current Java Virtual Machine is available.