Normal subgyrogroups of certain gyrogroups

Abstract

Suppose that (T;*) is a groupoid with a left identity such that each element a 2 T has a left inverse. Then T is called a gyrogroup if and only if (i) there exists a function gyr : T x T -Aut(T) such that for all a; b; c 2 T, a * (b * c) = (a * b) ? gyr[a; b]c, where gyr[a; b]c = gyr(a; b)(c); and (ii) for all a; b 2 T, gyr[a; b] = gyr[a ? b; b]. In this paper, the structure of normal subgyrogroups of certain gyrogroups are investigated.