                                                          src="../_images/math/4bc3e94a67870b41b7c20179693e889251e2c136.png"
                                                                                                       alt="B"/> and
                        <img class="math" src="../_images/math/4db5b6e16e06f929ce3f675c5e535d06ffb02ff7.png" alt="C"/>
                        (we have <img class="math" src="../_images/math/e0fca54dd1746e48d515d92ff8b0a0ca9fc35948.png"
                                 