Effective Procedure of Point-classification for the Equation

Two equations (1.1) and (1.3) which are bound with the transformation (1.2) are called point-equivalent equations. The problem of finding criteria for detecting pointequivalence for two given equations (1.1) and (1.3) is known as the problem of equivalence. This problem was studied in numerous papers (see [1–23]), some of them are classical papers and others are modern ones. Results of these papers were summed up in [24]. In that paper the complete description of point-equivalence classes for the equations of the form (1.1) is given. Some special classifying parameters play the key role in describing point-equivalence classes. Some of them are scalar invariants for the equation (1.1), others are the components of pseudotensorial fields of various weights.