Equivalence Groupof the (2+1)-Dimensional Variable Coefficient Caudrey-Dodd-Gibbon-Kotera-Sawada Equation

We derive the equivalence group for the (2+1)-dimensional variable-coefficient Caudrey-Dodd-Gibbon-Kotera-Sawada equation. Specifically, we determine the relationships among the coefficient functions that make this class equivalent to its constant-coefficient counterpart. In fact, this is the only case commonly found in the literature. Furthermore, we demonstrate that all known forms of the (2+1)-dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada and B-type Kadomtsev-Petviashvili equations can be transformed into a simpler form. Finally, we present the Lie symmetries for both constant- and variable-coefficient equations.