https://github.com/katydid/regex-deriv-coq

https://github.com/katydid/regex-deriv-coq

coq

Last synced: 4 days ago
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• Host: GitHub
• URL: https://github.com/katydid/regex-deriv-coq
• Owner: katydid
• License: apache-2.0
• Created: 2020-02-01T19:18:15.000Z (almost 5 years ago)
• Default Branch: main
• Last Pushed: 2024-12-03T15:55:09.000Z (about 2 months ago)
• Last Synced: 2025-01-15T01:23:07.034Z (7 days ago)
• Topics: coq
• Language: Coq
• Size: 1020 KB
• Stars: 21
• Watchers: 7
• Forks: 7
• Open Issues: 17
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE
  • Authors: AUTHORS

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README

        
![Check Proofs](https://github.com/awalterschulze/regex-reexamined-coq/workflows/Check%20Proofs/badge.svg)

**This learning exercise has come to an end. We are continuing work in this area [here](https://github.com/katydid/proofs)**

# Derivatives for Regular Expressions with Coq

This repo reexamines a few papers on regular expressions using Coq as a learning exercise.

We try to prove some things that are mentioned in the papers as a way to teach ourselves some Coq.

  - [Brzozowski](./src/Brzozowski)

    In this folder we explore proving theorems from the original paper [Derivatives of Regular Expressions - Janusz A Brzozowski](./src/Brzozowski/Derivatives%20of%20Regular%20Expressions%20-%20Janusz%20A%20Brzozowski.md)

    We have retyped and modified it a bit to aid readability.

  - [Coinduction](./src/Coinduction)

    In this folder we explore using coinduction to prove regular expressions are equivalent.

  - [Reexamined](./src/Reexamined)

    In this folder we explore a modern version of derivatives defined in the paper [Regular-expression derivatives reexamined](https://www.ccs.neu.edu/home/turon/re-deriv.pdf)

    This paper is a great introduction to using derivatives for regular expressions,

    since it has been not only been updated, but is also one of the easier papers to read.

  - [CoqStock](./src/CoqStock) standard library.

## Background

### Brzozowski's Derivatives of Regular Expressions

If you are unfamiliar with Brzozowski's Derivatives you can watch this video.



 



## Setup

1. Install Coq 8.13.0

2. Remember to set coq in your PATH. For example, in your `~/.bash_profile` add `PATH="/Applications/CoqIDE_8.13.0.app/Contents/Resources/bin/:${PATH}"` and run `$ source ~/.bash_profile`.

3. Run make in this folder.

Note:

 - `make cleanall` cleans all files even `.aux` files.

## Contributing

Please read the [contributing guidelines](https://github.com/awalterschulze/regex-reexamined-coq/blob/master/CONTRIBUTING.md).  They are short and shouldn't be surprising.

## Regenerate Makefile

Coq version upgrade requires regenerating the Makefile with the following command:

```

$ coq_makefile -f _CoqProject -o Makefile

```

## Pair Programming

We used to pair program. The schedule was posted as meetups events on [meetup.com](https://www.meetup.com/London-TyDD/)