https://github.com/dirkschumacher/nodepicosat

SAT solver PicoSAT for javascript
https://github.com/dirkschumacher/nodepicosat

logic logic-programming node-module picosat picosat-solver sat-solver

Last synced: about 1 month ago
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SAT solver PicoSAT for javascript

• Host: GitHub
• URL: https://github.com/dirkschumacher/nodepicosat
• Owner: dirkschumacher
• License: other
• Created: 2018-03-01T20:21:42.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-03-31T14:52:41.000Z (over 6 years ago)
• Last Synced: 2024-10-28T15:35:13.408Z (about 2 months ago)
• Topics: logic, logic-programming, node-module, picosat, picosat-solver, sat-solver
• Language: JavaScript
• Homepage:
• Size: 107 KB
• Stars: 8
• Watchers: 5
• Forks: 3
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# picosat for node

**Node bindings to the [PicoSAT solver release 965](http://fmv.jku.at/picosat/) by Armin Biere.** The PicoSAT C code is distributed under a MIT style license and is bundled with this package.

[![Build Status](https://travis-ci.org/dirkschumacher/nodepicosat.svg?branch=master)](https://travis-ci.org/dirkschumacher/nodepicosat)

[![npm version](https://img.shields.io/npm/v/picosat.svg)](https://www.npmjs.com/package/picosat)

## Install

```

npm install picosat

```

## Example

Suppose we want to test the following formula for satisfiability:

(*A* ⇒ *B*)∧(*B* ⇒ *C*)∧(*C* ⇒ *A*)

This can be formulated as a CNF (conjunctive normal form):

(¬*A* ∨ *B*)∧(¬*B* ∨ *C*)∧(¬*C* ∨ *A*)

This library expects the following equivalent notation:

```js

const fomula = [

  ['!A', 'B'],

  ['!B', 'C'],

  ['!C', 'A']

]

const {solveWithStrings} = require('picosat')

console.log(solveWithStrings(formula))

```

The result is an object:

```js

{

  satisfiable: true,

  statusCode: 'satisfiable', // may also be 'unsatisfiable' or 'unknown'

  solution: [ // negative values means false, positive true.

    -1, // A

    -2, // B

    -3 // C

  ]

}

```

We can also test for satisfiability assuming that a certain variable is true or false:

```js

const assumptions = [

  'A', // assume A is true

  '!C', // assume C is false

]

solveWithStrings(formula, assumptions)

```

## Integer interface

If you want to use integers to define the input, like other PicoSAT bindings in other languages expect it ([`rpicosat`](https://github.com/dirkschumacher/rpicosat#example), [`pycosat`](https://github.com/ContinuumIO/pycosat#example)), you can use `solve`.

```js

const solve = require('picosat')

const fomula = [

  [-1, 2], // !A, B

  [-2, 3], // !B, C

  [-3, 1] // !C, A

]

const assumptions = [

  -1 // assume A is false

]

const result = solve(formula, assumptions)

console.log('status code', result[0])

console.log('solution', result.slice(1))

```

```

statusCode 10 // 10: satisfiable, 20: unsatisfiable, otherwise unknown

solution [

  -1, // A

  -2, // B

  -3 // C

]

```

## Low-level interface

This package also provides a low-level interface that works directly on [`Buffer`s](https://nodejs.org/api/buffer.html), without encoding into/decoding from the format that *PicoSAT* works on:

```js

const encodeInt32Array = require('picosat/lib/encode')

const {solveUnsafe} = require('picosat')

const encodedFomula = encodeInt32Array([

  -1, 2, // !A, B

  0, // separator

  -2, 3, // !B, C

  0, // separator

  -3, 1, // !C, A

  0 // separator

])

const encodedAssumptions = encodeInt32Array([

  -1 // assume A is false

])

const result = solveUnsafe(encodedFormula, encodedAssumptions)

console.log('status code', result[0])

console.log('solution', result.slice(1))

```

```

statusCode 10 // 10: satisfiable, 20: unsatisfiable, otherwise unknown

solution [

  -1, // A

  -2, // B

  -3 // C

]

```

## License

This package is licensed under MIT.

The PicoSAT solver bundled with this package is licensed under MIT as well: Copyright (c) Armin Biere, Johannes Kepler University.