In this paper, we first find the set of orders of all elements in some special linear groups over the binary field. Then, we will prove the characterizability of the special linear group using only the set of its element orders.
In an earlier paper, the second author generalized Eilenberg’s variety theory by establishing a basic correspondence between certain classes of monoid morphisms and families of regular languages. We extend this theory in several directions. First, we prove a version of Reiterman’s theorem concerning the definition of varieties by identities, and illustrate this result by describing the identities associated with languages of the form , where are distinct letters. Next, we generalize the notions...
In this paper we study finite non abelian groups in which every proper normal subgroup and every proper epimorphic image is abelian. Also we study finite non nilpotent groups in which every normal subgroup and every proper epimorphic image is nilpotent and those finite soluble non nilpotent groups in which every proper normal subgroup is nilpotent.
In questa nota si studiano i gruppi finiti non supersolubili che hanno un solo sottogruppo normale massimale, e per cui ogni sottogruppo normale proprio e ogni immagine epimorfica propria è supersolubile.