Implements the multivariate classification methods of Alexander Alexandrovich Lyubishchev (1890-1972), as described in his 1943 manuscript 'Programma obshchey sistematiki' Lyubishchev (1943) < https://www.zin.ru/animalia/coleoptera/rus/lyubis05.htm> and published in Lubischew (1962) < https://www.jstor.org/stable/2527894>. Provides divergence_coefficient() for measuring separation between groups on continuous features, scatter_ellipse() for fitting covariance ellipses per class, transgression() for detecting ellipse overlap, and classify() for Bayesian posterior classification. These methods predate and are more general than the binary-character similarity coefficients of Sokal and Sneath (1963) that appear in other R packages.