During November 2025, Muzumayao focused on improving interval arithmetic within the sympy/sympy repository by addressing a correctness issue in the AccumBounds.intersect method. Using Python and leveraging mathematical expertise, Muzumayao revised the intersection logic to ensure consistent results, particularly for edge cases involving equal maximum values. The work included adding comprehensive tests to validate the new behavior and to guard against future regressions. This targeted change enhanced the robustness of interval computations in sympy, reducing the risk of subtle bugs. The contribution demonstrated careful attention to detail and a methodical approach to software testing and mathematical correctness in Python.