The Theorem Prover Museum

Theorem provers are software systems that can find or check proofs for conjectures given in some logic. Research in theorem proving system started with the logical theorist 1955 and has led to a succession of systems since.

Theorem provers are complex software systems that have pushed the envelope of artificial intelligence and programming, and as such they constitute important cultural artefacts.

With the current wave of retirements of the original principal investigators there is good chance that the systems are lost, when their group servers are shut down. This web site aims to preserve the ones we can still get our hands on. This idea is compatible with the Software Heritage initiative, and contributes since it is based on GitHub repositories.

The term “museum” may be sound bit ambitious, since the exhibition and didactic interpretation of the theorem provers is beyond our scope (and perhaps abilities). But the foremost function of a museum is the conservation of artefacts, which is what the “theorem prover museum” project intends to do.

This site is the front-end to a collection of source code repositories for theorem provers (see below). Note that it is not the purpose of this site to keep the theorem proving systems running (in many cases the compilers and dependencies have moved on, making this very difficult), but only to archive the source code for academic study and aggregate meta-data about the systems. In particular this should lower the barrier of archiving systems here.

See also most wanted list, systems believed lost, how to contribute, Community, project/issues.

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Encyclopedia of proof systems, Wikipedia page, … more.

All theorem provers start out as active systems, eventually development gets discontinued as developers retire or move to newer systems. Therefore we also maintain a list of source code repositories of active theorem provers.

Theorem Provers


The IMPS Theorem Prover.

authors:William M. Farmer, Joshua D. Guttman, F. Javier Thayer
language:Scheme, Common Lisp

The Markgraph Karl Refutation Procedure, a graph-based resolution theorem prover

authors:Jörg Siekmann, Jürgen Ohlbach, Axel Präcklein
language:Common Lisp

A theorem prover for higher-order logic based on proof planning.

authors:Jörg Siekmann, Detlef Fehrer, Christoph Benzmüller, Michael Kohlhase, Manfred Kerber
language:Common Lisp

An Inductive Theorem Prover

authors:Dieter Hutter

The first theorem prover for first-order logic with equality from the Argonne group that was widely distributed.

authors:William McCune

The Argonne Model generator.

authors:William McCune

Prover9 is the successor to Otter

authors:William McCune

Mace4 is the successor of Mace.

authors:William McCune

The Prolog Equation Solving System (PRESS) pioneered work on what is now called proof planning.

authors:Alan Bundy

The original Edinburgh LCF


TPS is an interactive, semi-automatic, and automatic Theorem Proving System for first-order logic and higher-order logic.

authors:Peter Andreas, Frank Pfenning, Dale Miller, Sunil Issar, Hongwei Xi, Mathhew Bishop, Chad Brown
language:Comon Lisp

ETPS is a subsystem of TPS designed for interactive use by students in logic courses.

authors:Peter Andreas, Frank Pfenning, Dale Miller, Sunil Issar
language:Common Lisp

The HOL System is an environment for interactive theorem proving in a higher-order logic. Its most outstanding feature is its high degree of programmability through the meta-language ML.

authors:Mike Gordon, Tom Melham, and numerous other contributors

The rational reconstruction of HOL88

authors:Konrad Slind, Graham Birtwistle

SRIs New Automated Reasoning Kit

authors:Mark Stickel
Repository: R1

an early theorem prover written in SNOBOL

authors:Wolfgang Bibel

A general-purpose instance-based first-order automated theorem proving algorithm


A Semantically Guided First-Order Theorem Prover


An improved version of the original Boyer-Moore theorem prover

Repository: R1

A Prolog implementation of the proof planner Clam (in the clam2 development branch) and the associated theorem prover, oyster.

authors:Alan Bundy
Clam 3

Prolog implementation of proof planner with critics, and some higher-order unification, in the v3 branch of Clam.


A proof planning system that support proof planning over higher-order domains.


A Distributed and Learning Equational Prover.


A tool for automated verification of formal mathematical texts.

Repository: R1

A proof checker and interactive theorem prover for dependently typed set theory.

authors:Chad Brown

A first-order theorem prover based on the connection method.

authors:Johann Schumann, Wolfgang Bibel

A theorem prover based on the PTTP paradigm.

home page:
authors:Gerd Neugebauer & Uwe Petermann
license:GPL V1
language:(ECLiPSe) Prolog
Logic Theorist

The first theorem prover by Newell and Simon.

authors:Alan Newell, Herbert Simon

Rewrite and Decision Procedure Laboratory

authors:Alessandro Armando, Luca Compagna, Silvio Ranise
license:GPL 3.0
Repository: R1

authors:J Strother Moore, Robert S. Boyer (Grant O. Passmore: OCaml Reimplementation)
language:Pure Lisp
note:the code is still linked from the ACL github repository.

The prover of the Robbins Conjecture

home page:
authors:William McCune

an early interactive proof development system for various type theories

home page:
authors:Randy Pollack
development:<= 1999
note:See ​for some old documents.
Cambridge LCF

Edinburgh LCF re-implemented in Standard ML

language:Standard ML