lejeunerenard / symbolic-sets

A library for symbolic manipulation of sets and their operators as a tree.

Symbolic Sets

A library for symbolic manipulation of sets and their operators as a tree.

Usage

import { UnionNode, IntersectNode, Term } from '@lejeunerenard/symbolic-sets'

// Construct a tree for (A ∩ B) ∪ (C ∩ D)
const expression = new UnionNode([
  new IntersectNode([
    new Term('A'),
    new Term('B')
  ]),
  new IntersectNode([
    new Term('C'),
    new Term('D')
  ])
])

// Compute the Conjunctive Normal Form tree
const cnf = expression.toCNF()

// Logs "((C ∪ A) ∩ (C ∪ B) ∩ (D ∪ A) ∩ (D ∪ B))"
console.log(cnf.toString())

Install

npm install lejeunerenard/symbolic-sets

API

new Universal()

A node that represents the "Universal" set, eg the set that contains all elements.

new Null()

A node that represents the "Null" set, eg the set that contains nothing.

new Term(string)

A node that represents a simple set denoted by the string.

.simplify()

Returns a new Term copy as a term is already simplified.

new OpNode(type, children)

A node that represents a operator node of type type operating on children nodes. Current supported operator types are OP_UNION, OP_INTERSECT & OP_COMPLEMENT.

Note that OP_UNION & OP_INTERSECT types require 2 or more children. OP_COMPLEMENT requires exactly 1 children.

.simplify()

Recursively reduces the node and its children into a simplified form with less nodes.

.toCNF()

Recursively reduces the node into its Conjunctive Normal Form aka a intersection of unions.

new UnionNode(children)

A shortcut for new OpNode(OP_UNION, children).

new IntersectNode(children)

A shortcut for new OpNode(OP_INTERSECT, children).

new ComplementNode(child)

A shortcut for new OpNode(OP_COMPLEMENT, [child]).