Zadig approach instructive, and wrote in his 1880 article "On the Method of "Zadig"": Edgar Allan Poe may have been inspired by "Zadig" when he created C. Auguste Dupin in "The Murders in the Rue Morgue", which Poe called a "tale of ratiocination" and which established the modern detective fiction genre. Émile Gaboriau and Arthur Conan Doyle were perhaps also influenced by "Zadig". As Barzun and Taylor put it in "A Catalogue of Crime": "However implausible and "agrarian" his method, he is the first systematic detective in modern literature, and that priority itself adds to his troubles in the story until
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