Function round

src/compute-engine/interval/elementary.ts:489–494

(x: Interval | IntervalResult)

    if (m !== 0) vs = scalePow2(v, -n * m);
  }

  const guess = Math.pow(vs, 1 / n);
  let lo = guess;
  let move = 1;
  for (let attempt = 0; powChainUp(lo, n) > vs; attempt++) {
    // Giving up is sound, not merely conservative: 0 is below every root of a
    // positive number, and `Infinity` is above every root.
    if (attempt >= MAX_ROOT_SEARCH_ATTEMPTS) {
      lo = 0;