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How to construct the discrete symmetries of partial differential equations. (English) Zbl 1035.35005
An algorithm for computation of all discrete point symmetries on a known group of Lie point symmetries of a given partial differential equation is given. It is applied to the determination of the discrete point symmetries for Burgers equation, spherical Burgers equation and Harry-Dym equation. This approach is extended on some types of nonlocal symmetry.
MSC:
35A30Geometric theory for PDE, characteristics, transformations
58J70Invariance and symmetry properties