| Real and imaginary parts of the continuation of  over the  . The imaginary part is a faithful representation of the Riemann surface of  . Imaginary parts of the continuation of  over the  . The two square root branch points at  are clearly visible. The viewpoint is from the left half‐plane. Imaginary parts of the continuation of  over the Riemann sphere. The branch points are at the intersection of the equator with the  ‐plane |