Function fuTestHelper

test/compute-engine/simplify.test.ts:1389–1392

(a: string, b: string)

    expect(e.subs({ u: 1, w: -1 }).N().im).toBeCloseTo(0, 10);
  });

  test('(−u)² keeps even-power sign (no stray negation)', () => {
    const sq = ce.expr(['Negate', 'u']).pow(2);
    expect(sq.subs({ u: 3 }).N().re).toBeCloseTo(9, 10);
  });

  test('exact numeric radicals still merge: √2·√3 = √6', () =>