G4ip

Description

Implementation of a theorem prover for intuitionistic propositional logic using G4ip in Haskell.

Fork of cacay/G4ip.

G4ip rules

Improvements over the original code

• proof trees are now constructing explicitly
• added proposition parser
• added exporting of the proof tree to LaTeX

File Structure

• G4ipProver/Proposition.hs -- Definition of propositions and some syntactic sugar
• G4ipProver/Prover.hs -- The actual theorem prover
• G4ipProver/Parser.hs -- Parser for propositions
• G4ipProver/LaTeXExporter.hs -- Exporter for proofs
• G4ipProver.hs -- Re-exports the above modules
• Main.hs -- g4ip-prover binary

Running

Use stack: stack exec g4ip-prover

Usage

g4ip-prover [OPTIONS] PROPOSITION
g4ip-prover [OPTIONS]

If the proposition was not specified, the user will be prompted to enter it interactively.

Options

--proof-header <file>       Template header file for proof.
                            Default value: static/proof-header.txt
--proof-footer <file>       Template footer file for proof.
                            Default value: static/proof-footer.txt
--context-header <file>     Template header file for context.
                            Default value: static/context-header.txt
--context-footer <file>     Template footer file for context.
                            Default value: static/context-footer.txt
--proof-file <file>         Proof file name. If the file exists, it will be overwritten.
                            Default value: output/proof.tex
--context-file <file>       Context file name. If the file exists, it will be overwritten.
                            Default value: output/context.tex

Proposition syntax

Variables must consist of lower-case english characters and numbers.
Propositional connectives (with precedence level):
   ~ , -    - negation, 1
   /\, &    - conjunction, 2
   \/, |    - disjunction, 3
   ->, =>   - implication, 4
   <-, <=   - implication, 4
   <->, <=> - equivalency, 5
Logical constants:
   T - True
   F - False

Converting to PDF

Use bussproofs and pdflatex.