ABSTRACT
The notion of supplementing radical is redefined for Plotkin radicals of nonassociative rings (algebras, Ω-groups, near-rings, etc) and investigated. If the essential closure of a Plotkin radical class is contained in a unique minimal Kurosh-Amitsur semisimple class, then the supplementing radical exists, is unique, and coincides with the one of the usual definition. Any hereditary Plotkin radical has a unique supplementing radical. If in the universal class considered, every semisimple class is hereditary, then every Plotkin radical has a unique supplementing radical. Supplementing radicals are given as upper radicals of subdirectly irreducible rings. Results are applied to Andrunakievich s-varieties, in particular to alternative algebras.
