Sherlock Holmes such that many have believed him to be not a fictional character but a real individual; numerous literary and fan societies have been founded that pretend to operate on this principle. Widely considered a British cultural icon, the character and stories have had a profound and lasting effect on mystery writing and popular culture as a whole, with the original tales as well as thousands written by authors other than Conan Doyle being adapted into stage and radio plays, television, films, video games, and other media for over one hundred years. Edgar Allan Poe's C. Auguste Dupin is generally acknowledged
Dupin cyclide that the class of Dupin cyclides is invariant under Möbius (or conformal) transformations. In complex space formula_2 these three latter varieties can be mapped to one another by inversion, so Dupin cyclides can be defined as inversions of the torus (or the cylinder, or the double cone). Since a standard torus is the orbit of a point under a two dimensional abelian subgroup of the Möbius group, it follows that the cyclides also are, and this provides a second way to define them. A third property which characterizes Dupin cyclides is that their curvature lines are all circles (possibly through