The tableaux package

[Tags: bsd3, program]

This is a simple web-based interactive theorem prover using semantic tableaux for propositional and first-order logic (cf. First-Order Logic, Raymond Smullyan, Dover). It allows step-by-step construction of proofs and runs on any web server supporting the CGI interface.

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Versions0.1, 0.2
Change logNone available
Dependenciesbase (==4.*), cgi (>=3001.1), containers, html (>=1.0), mtl (>=1.1), parsec (>=2.1), QuickCheck (>=2.1) [details]
AuthorPedro Vasconcelos <>
MaintainerPedro Vasconcelos <>
CategoryTheorem Provers
UploadedFri Apr 5 16:05:04 UTC 2013 by PedroVasconcelos
Downloads462 total (10 in last 30 days)
0 []
StatusDocs not available [build log]
Last success reported on 2015-11-13 [all 5 reports]


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Readme for tableaux-0.2

Tableaux theorem prover for first order logic

This is a simple interactive theorem prover for first order logic
using the tableaux method. The "tableau" is a tree depicting a proof
where each node is a sentence; linear branches represent conjunctions
while forks represent disjunctions. At each step one introduces
new nodes by "breaking down" a formula into its logical
consequences. To prove a formula F it is sufficient to show that
~F is unsatisfiable, i.e. that all branches of the tableau lead
to contradictions.
The prover is implemented in Haskell as a CGI that shows the
current proof tree and highlights one focus node
(initially the whole formula). The interface is consists of:
* navigate the proof tree (point and click)
* expand the current node 
* apply resolution to the branch with the current node

Closed branches end in a "false" sentence, i.e. have been shown to 
be inconsistent/unsatisfiable. To prove the original theorem one must close
all branches.

Pedro Vasconcelos <>, 2009.
Tree "zipper" implementation by Krasimir Angelov & Iavor S. Diatchki, 2008.

References: First Order Logic, R. Smullyan, Dover.
On the web: