Sherlock Holmes primarily relies on abduction: inferring an explanation for observed details. "From a drop of water", he writes, "a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other". In "A Scandal in Bohemia", Holmes infers that Watson had got wet lately and had "a most clumsy and careless servant girl". When Watson asks how Holmes knows this, the detective answers: In the first Holmes story, "A Study in Scarlet", Dr. Watson compares Holmes to C. Auguste Dupin, Edgar Allan Poe's fictional detective, who employed a similar methodology. Alluding to
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