Generalized Derivations of Associative Algebras

In their paper [6], Leger and Luks introduced the notion of a generalized derivation in nonassociative algebras and got several results for generalized derivations of Lie algebras. This generalized derivation is closely related to Breˇsar's and the second author's generalized derivations in associative rings. In this note, we discuss the relations of these generalized derivations.