Hercule Poirot and Frank Howel Evans' Monsieur Poiret, a retired Belgian police officer living in London. A more obvious influence on the early Poirot stories is that of Arthur Conan Doyle. In "An Autobiography", Christie states, "I was still writing in the Sherlock Holmes tradition – eccentric detective, stooge assistant, with a Lestrade-type Scotland Yard detective, Inspector Japp". For his part, Conan Doyle acknowledged basing his detective stories on the model of Edgar Allan Poe's C. Auguste Dupin and his anonymous narrator, and basing his character Sherlock Holmes on Joseph Bell, who in his use of "ratiocination" prefigured Poirot's reliance on his
Dupin cyclide also used to refer to a more general class of quartic surfaces which are important in the theory of separation of variables for the Laplace equation in three dimensions. Dupin cyclides were investigated not only by Dupin, but also by A. Cayley und J.C. Maxwell. Today, Dupin cylides are used in computer-aided design (CAD), because cyclide patches have rational representations and are suitable for blending canal surfaces (cylinder, cones, tori, and others). There are several equivalent definitions of Dupin cyclides. In formula_1, they can be defined as the images under any inversion of tori, cylinders and double cones. This shows