Function floor

src/compute-engine/interval/elementary.ts:420–430

(x: Interval | IntervalResult)

      acc = prodExact(acc, sq, p) ? p : nextUp(p);
    }
    k = Math.floor(k / 2);
    if (k > 0) {
      const p = sq * sq;
      sq = prodExact(sq, sq, p) ? p : nextUp(p);
    }
  }
  return acc;
}

/** A LOWER bound of `v^n`, by the same chain as `powChainUp` with every
 *  uncertified product moved one ulp down. An overflowed product answers
 *  `Number.MAX_VALUE`, which is below the true value it stands for. */
function powChainDown(v: number, n: number): number {
  let acc = 1;