Automated theorem proving is the subfield of automated reasoning concerned with constructing formal proofs of mathematical or logical statements by machine. Given a set of axioms and a conjecture expressed in a formal logic, an automated theorem prover searches for a derivation that establishes the conjecture as a consequence of the axioms. Techniques span resolution, tableaux, term rewriting and decision procedures, and underpin formal verification, mathematics and AI reasoning.

Overview

  • An automated theorem prover takes a logical theory and a goal and attempts to find a proof using inference rules, deciding entailment where the logic is decidable and searching otherwise.
  • The field separates fully automatic provers from interactive proof assistants, which combine machine search with human guidance. Both descend from the formalisation of mathematics in first-order and higher-order logics.
  • Provers exploit normal forms, indexing, and heuristics to tame the vast search space, since proof search is in general undecidable for expressive logics.

Mechanisms

  • Resolution: refutation-based search over clauses in conjunctive normal form.
  • Tableaux: systematic construction of models to test satisfiability.
  • Term rewriting: directed equational reasoning to normalise expressions.
  • Decision procedures: complete algorithms for decidable fragments such as linear arithmetic.
  • Proof search heuristics: ordering, subsumption and clause selection to prune branches.

Applications

  • Formal verification of processors, protocols and safety-critical software.
  • Machine-checked mathematics and large formalisation projects.
  • Backends for Constraint Satisfaction and program analysis.
  • Reasoning components within neuro-symbolic and agentic AI systems.

Provenance