mathml-to-mathjs

Convert MathML strings into mathjs-compatible expression strings. Works in both browser and Node.js.

Install

npm install mathml-to-mathjs

If you're running in Node.js, also install the peer dependency:

npm install @xmldom/xmldom

In the browser, the native DOMParser is used automatically — no extra install needed.

Usage

import { parse } from 'mathml-to-mathjs';

const mathml = `
  <math xmlns="http://www.w3.org/1998/Math/MathML">
    <mrow>
      <mi>b</mi><mo>+</mo><mi>a</mi>
    </mrow>
  </math>
`;

parse(mathml); // → "b + a"

With mathjs — validate equivalence

import { parse } from 'mathml-to-mathjs';
import { simplify, evaluate } from 'mathjs';

function areEquivalent(mathml1, mathml2) {
  const expr1 = parse(mathml1);
  const expr2 = parse(mathml2);

  // Symbolic check
  const diff = simplify(`(${expr1}) - (${expr2})`);
  if (diff.toString() === '0') return true;

  // Numeric check across test points
  const points = [
    { x: 1, a: 2, b: 3 },
    { x: -2, a: 0.5, b: -1 },
    { x: 3.7, a: 10, b: 0.1 },
  ];

  return points.every(pt => Math.abs(evaluate(expr1, pt) - evaluate(expr2, pt)) < 1e-9);
}

Supported MathML tags

| Tag | Output | |-----|--------| | mn | number literal | | mi | variable / function name | | mo | operator (unicode operators normalised to ASCII) | | mrow, math, mstyle, mpadded | transparent grouping | | mfrac | (num) / (den) | | msqrt | sqrt(...) | | mroot | nthRoot(base, index) | | msup | (base)^(exp) | | msub | base + subscript concatenated (e.g. x1) | | msubsup | (base)^(exp) | | mfenced | (...) | | munder, mover, munderover | base only | | mtable / mtr / mtd | [[a, b], [c, d]] | | semantics | first child only | | mtext, mphantom, annotation | skipped |

Options

parse(mathml, options?)

options.tagHandlers

Override or extend any tag's behaviour:

parse(mathml, {
  tagHandlers: {
    // include mtext content instead of skipping it
    mtext: (node, convert) => node.textContent ?? '',
  },
});

License

MIT