ACL2 Version 
2.7
A programming language in which you can model computer systems and a 
tool to help prove properties of those models. Available under GPL and runs on 
various platforms. Includes related download 
links.
http://www.cs.utexas.edu/users/moore/acl2/
Automated Reasoning 
Project
Web resource provided by research group. Includes access to 
software developed by the team, coverering such projects as FINDER (Finite 
Domain Enumerator), MaGIC (Matrix Generator for Implication Connectives) and 
Kripke (A theorem prover for the relevant logic 
LR).
http://cslab.anu.edu.au/ar/
Bertrand
First-order 
satisfiability checker and prover for the 
Macintosh.
http://www.humnet.ucla.edu/humnet/phil/grads/herzberg/Bertrand.html
Church
Program 
understands the different types of lambda expressions, can extract lists of 
variables (both free and bound) and subterms, and can simplify complicated 
expressions. Uses Python.
http://www.alcyone.com/software/church/
Database of Existing 
Mechanized Reasoning Systems
A list (>50 entries) of automatic 
resolution provers (like Otter), interactive provers (like PVS) and other 
mechanized reasoning 
tools.
http://www-formal.stanford.edu/clt/ARS/systems.html
DC Proof 
Online
New proof-writing software to teach the fundamentals of logic and 
proof. Enables users/students to write error-free proofs by selecting rules of 
inference, axioms, etc. from convenient drop-down menus. Includes tutorial and 
exercises.
http://www.dcproof.com
DELORES
A 
forward-chaining reasoning engine for defeasible logic, a less expressive but 
more efficient nonmonotonic 
logic.
http://www.dfki.uni-kl.de/~miller/delores/
Gateway to 
Logic
A collection of web-based logic programs offering a number of 
logical functions: interactively or automatically build proofs, check theorems, 
and operate on propositional logic 
formulae.
http://logik.phl.univie.ac.at/~chris/formular-uk.html
Isabelle
A 
generic theorem proving environment developed at Cambridge University (Larry 
Paulson) and TU Munich (Tobias Nipkow). Includes logic, documentation and free 
download.
http://www.cl.cam.ac.uk/Research/HVG/Isabelle/
llprover
A 
linear logic prover that searches a cut-free proof for the given two-sided 
sequent of first-order linear 
logic.
http://bach.scitec.kobe-u.ac.jp/llprover/
Logic Software from 
CSLI
By Jon Barwise and John 
Etchemendy.
http://www-csli.stanford.edu/hp/Logic-software.html
LOOM
A language 
and environment for constructing intelligent applications. It is a research 
project in the Artificial Intelligence research group at the University of 
Southern California's Information Sciences Institute. The goal of the project is 
to develop and field advanced tools for knowledge representation and reasoning 
in Artificial Intelligence.
http://www.isi.edu/isd/LOOM/LOOM-HOME.html
Ludwig
Application that draws 
truth-tables for propositional logic formulae. Available for free download and 
web use.
http://www.mintlogic.com/ludwig/
LWB
Logics 
Workbench.
http://www.lwb.unibe.ch/
MUltlog
Takes 
as input the specification of a finitely-valued first-order logic and produces a 
sequent calculus, a natural deduction system, and clause formation rules for 
this logic.
http://www.logic.at/multlog/
MUltseq
A 
generic sequent prover for propositional finitely-valued 
logics.
http://www.logic.at/multseq/
Paradox
A tool 
that processes first-order logic problems and tries to find finite-domain models 
for them; written by Koen Claessen and Niklas Sörensson. Haskell and C++; free 
download under GPL.
http://www.cs.chalmers.se/~koen/paradox/
Proof 
General
Comprehensive Gnu-Emacs and XEmacs interface for several theorem 
provers including Coq, Isabelle, Lego, and 
Phox.
http://proofgeneral.inf.ed.ac.uk
ProofPower
A 
suite of tools supporting specification and proof in Higher Order Logic (HOL) 
and in Z notation.
http://www.lemma-one.com/ProofPower/index/
PROTEIN
A 
PROver with a Theory Extension INterface. Theorem prover for first-order clause 
logic, written in ECRC's Prolog-dialect ECLiPSe. Free download, 
documentation.
http://www.uni-koblenz.de/ag-ki/Implementierungen/Protein/
PVS
The PVS 
Specification and Verification System. Available for Sparc machines with Solaris 
2 and Intel x86 Machines with Linux compatible with Redhat 5 or later. Required 
is Emacs (version 19 or later), recommended LaTeX and Tcl/Tk. Download by 
FTP.
http://pvs.csl.sri.com/
SwitchMin Digital 
Circuit Minimizer
Tool for minimizing boolean logic 
functions.
http://incolor.inetnebr.com/double/softlib/switchmin.html
The Coq 
Project
Deals with effectively machine-checked formal mathematics. In 
practice, this includes the study of mathematical formalisms well-suited for 
implementations, the implementations themselves and the use of these for various 
applications. Focuses on software correctness 
proofs.
http://pauillac.inria.fr/coq/
Tree Proof 
Generator
An implementation of the semantic tableaux method for classical 
propositional and predicate logic, written in 
JavaScript/DOM.
http://www.umsu.de/logik/trees
VeriFun
A 
semi-automated system for the verification of statements about programs written 
in a functional programming language. The system is capable of following 
fully-automated routines for theorem proving and hypotheses formation, as well 
as operating interactively when these reoutines 
fail.
http://www.informatik.tu-darmstadt.de/pm/verifun/
Visual Turing
A 
graphical IDE for creating, running and debugging Turing machines. Freeware for 
Windows 95/98/NT/2000.
http://www.cheransoft.com/vturing/
WinKE: A Proof 
Assistant for Teaching Logic
WinKE is an interactive proof assistant 
based on analytic tableaux, and designed for the teaching of deductive 
reasoning. Ordering information is available at this site, as are academic 
papers on the design of the 
software.
http://www.dcs.kcl.ac.uk/staff/endriss/WinKE/