Function gcd

src/compute-engine/boxed-expression/factor.ts:497–504

(a: number, b: number)

  for (const p of pDivisors) {
    for (const q of qDivisors) {
      const pos = p / q;
      const neg = -p / q;
      if (!seen.has(pos)) {
        seen.add(pos);
        candidates.push([p, q]);
      }
      if (!seen.has(neg)) {
        seen.add(neg);
        candidates.push([-p, q]);
      }
    }