Some commutativity criteria for 3-prime near-rings

In the present paper, we introduce the notion of *-generalized derivation in near-ring N and investigate some properties involving that of *-generalized derivation of a *-prime near-ring N which forces N to be a commutative ring. Some properties of generalized semiderivations have also been given in...

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Автор: Raji, A.
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Опубліковано: Інститут прикладної математики і механіки НАН України 2021
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Цитувати:Some commutativity criteria for 3-prime near-rings / A. Raji // Algebra and Discrete Mathematics. — 2021. — Vol. 32, № 2. — С. 280-298. — Бібліогр.: 10 назв. — англ.

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spelling irk-123456789-1887542023-03-15T01:27:27Z Some commutativity criteria for 3-prime near-rings Raji, A. In the present paper, we introduce the notion of *-generalized derivation in near-ring N and investigate some properties involving that of *-generalized derivation of a *-prime near-ring N which forces N to be a commutative ring. Some properties of generalized semiderivations have also been given in the context of 3-prime near-rings. Consequently, some well known results have been generalized. Furthermore, we will give examples to demonstrate that the restrictions imposed on the hypothesis of various results are not superŕuous. 2021 Article Some commutativity criteria for 3-prime near-rings / A. Raji // Algebra and Discrete Mathematics. — 2021. — Vol. 32, № 2. — С. 280-298. — Бібліогр.: 10 назв. — англ. 1726-3255 DOI:10.12958/adm1439 2020 MSC: 16N60, 16W25, 16Y30 http://dspace.nbuv.gov.ua/handle/123456789/188754 en Algebra and Discrete Mathematics Інститут прикладної математики і механіки НАН України
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
language English
description In the present paper, we introduce the notion of *-generalized derivation in near-ring N and investigate some properties involving that of *-generalized derivation of a *-prime near-ring N which forces N to be a commutative ring. Some properties of generalized semiderivations have also been given in the context of 3-prime near-rings. Consequently, some well known results have been generalized. Furthermore, we will give examples to demonstrate that the restrictions imposed on the hypothesis of various results are not superŕuous.
format Article
author Raji, A.
spellingShingle Raji, A.
Some commutativity criteria for 3-prime near-rings
Algebra and Discrete Mathematics
author_facet Raji, A.
author_sort Raji, A.
title Some commutativity criteria for 3-prime near-rings
title_short Some commutativity criteria for 3-prime near-rings
title_full Some commutativity criteria for 3-prime near-rings
title_fullStr Some commutativity criteria for 3-prime near-rings
title_full_unstemmed Some commutativity criteria for 3-prime near-rings
title_sort some commutativity criteria for 3-prime near-rings
publisher Інститут прикладної математики і механіки НАН України
publishDate 2021
url http://dspace.nbuv.gov.ua/handle/123456789/188754
citation_txt Some commutativity criteria for 3-prime near-rings / A. Raji // Algebra and Discrete Mathematics. — 2021. — Vol. 32, № 2. — С. 280-298. — Бібліогр.: 10 назв. — англ.
series Algebra and Discrete Mathematics
work_keys_str_mv AT rajia somecommutativitycriteriafor3primenearrings
first_indexed 2025-07-16T10:57:32Z
last_indexed 2025-07-16T10:57:32Z
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fulltext © Algebra and Discrete Mathematics RESEARCH ARTICLE Volume 32 (2021). Number 2, pp. 280ś298 DOI:10.12958/adm1439 Some commutativity criteria for 3-prime near-rings A. Raji Communicated by G. Pilz Abstract. In the present paper, we introduce the notion of ∗- generalized derivation in near-ring N and investigate some properties involving that of ∗-generalized derivation of a ∗-prime near-ring N which forces N to be a commutative ring. Some properties of generalized semiderivations have also been given in the context of 3- prime near-rings. Consequently, some well known results have been generalized. Furthermore, we will give examples to demonstrate that the restrictions imposed on the hypothesis of various results are not superŕuous. 1. Introduction Throughout this paper N will be a near-ring with multiplicative center Z(N). A near-ring N is said to be 3-prime if xNy = {0} for x, y ∈ N implies x = 0 or y = 0. It is called 3-semiprime if xNx = {0} implies x = 0. Recalling that N is called 2-torsion free if (N,+) has no elements of order 2; and N is called zero-symmetric if 0 ·x = x · 0 = 0 for all x ∈ N . For any x, y ∈ N ; as usual [x, y] = xy − yx and x ◦ y = xy + yx will denote the well-known Lie and Jordan products respectively. An additive mapping ∗ : N → N is called an involution if (xy)∗ = y∗x∗ and (x∗)∗ = x for all x, y ∈ N . A near-ring N equipped with an involution ∗ is said to be ∗-prime if xNy = xNy∗ = {0} implies x = 0 or y = 0. Obviously a left 2020 MSC: 16N60, 16W25, 16Y30. Key words and phrases: 3-prime near-rings, 3-semiprime near-rings, involution, ∗-derivation, semiderivation, commutativity. https://doi.org/10.12958/adm1439 A. Raji 281 (resp. right) near-ring with involution is in fact distributive, and hence also zero-symmetric. Indeed, let N be a left near-ring with involution ∗, and let x, y, z,∈ N . Then ((x+ y)z)∗ = z∗(x∗ + y∗) = z∗x∗ + z∗y∗. Applying ∗ to both sides, we obtain (x+ y)z = (z∗x∗ + z∗y∗)∗ = x∗∗z∗∗ + y∗∗z∗∗ = xz + yz. Clearly, a near-ring with an involution is not necessarily a ring. Indeed, in Example 1, since the addition law in N is not commutative, N cannot be a ring. The commutativity of 3-prime near-rings with derivation was initiated by Bell and Mason in [3]. Over the last two decades, a lot of work has been done on this subject. Recently, in [2], Ashraf and Siddeeque deőned the following notations: An additive mapping d : N → N is called a ∗-derivation if there exists an involution ∗ : N → N such that d(xy) = d(x)y∗ + xd(y), for all x, y ∈ N . An additive mapping F : N → N is called a left ∗-multiplier if F (xy) = F (x)y∗ hold for all x, y ∈ N . Motivated by these concepts, we introduce the concepts of ∗-generalized derivation in near-rings as follows: An additive mapping F : N → N is called a ∗-generalized derivation if there exist a ∗-derivation d of N such that F (xy) = F (x)y∗ + xd(y) for all x, y ∈ N. One may observe that the concept of ∗-generalized derivation includes the concept of ∗-derivation and left ∗-multiplier. Hence it should be interesting to extend some results concerning these notions to ∗-generalized derivation. An additive mapping δ : N → N is said to be a derivation if δ(xy) = xδ(y)+δ(x)y for all x, y ∈ N , or equivalently, as noted in [10], that δ(xy) = δ(x)y + xδ(y) for all x, y ∈ N . An additive mapping f : N → N is said to be a generalized derivation on N if there exists a derivation δ : N → N such that f(xy) = f(x)y + xδ(y) for all x, y ∈ N . An additive mapping d : N → N is called semiderivation if there is a function g : N → N such that d(xy) = xd(y) + d(x)g(y) = g(x)d(y) + d(x)y and d(g(x)) = g(d(x)) for all x, y ∈ N , or equivalently, as noted in [5], that d(xy) = d(x)g(y) + xd(y) = d(x)y + g(x)d(y) and d(g(x)) = g(d(x)) 282 Commutativity criteria for 3-prime near-rings for all x, y ∈ N . Obviously, any derivation is a semiderivation, but the converse is not true in general (see [5]). An additive mapping F : N → N is called generalized semiderivation if there is a semiderivation d : N → N associated with a function g : N → N such that F (xy) = F (x)y + g(x)d(y) = d(x)g(y) + xF (y) for all x, y ∈ N. Of course any semiderivation is a generalized semiderivation. Moreover, if g is the identity map of N , then all generalized semiderivations associated with g are merely generalized derivations of N . Recently, many researchers have studied commutativity of prime and semiprime rings admitting suitably constrained additive mappings, as: automorphisms, derivations and involutions acting on appropriate subsets of the rings (see, for example, Bell and Mason [3]; Bresar and Vukman [6]; Fong [7]; Oukhtite and Salhi [8]). Being motivated by their invaluable research, it is natural then to ask if we can apply the involution so as to study the structure of a near-ring. In this paper, őrstly we would like to study the structure of a ∗-prime left near-ring and 3-semiprime left near-rings as having an involution. More precisely, we shall prove that a ∗-prime near-ring must be a commutative ring. Secondly, some results concerning composition of generalized semiderivation on a 3-prime right near-ring will be exposed. As for terminologies used here without mention, we refer to Pilz [9]. 2. Main results In [6] M. Bresar and J.Vukman introduced the notion of ∗-derivation (resp. reverse ∗-derivation) in rings and proved that if a prime ∗-ring admits a nonzero ∗-derivation (resp. reverse ∗-derivation), then the ring is commutative. This result was extended to 3-semiprime ring by S. Ali [1], who proved that if a 3-semiprime ∗-ring R admits a ∗-derivation (resp. reverse ∗-derivation) d, then d maps R into Z(R) where Z(R) is the center of R. Further, Ashraf and Seddeeque [2] showed that a 3-prime ∗-near-ring N with a nonzero ∗-derivation d, must be commutative. Motivated by these results mentioned above, we succeeded in establishing the following results: Theorem 1. Let N be a ∗-prime near ring. If N admits a nonzero ∗-generalized derivation F , then N is a commutative ring. A. Raji 283 Proof. For all x, y, z ∈ N , we have F (xyz) = F (xy)z∗ + xyd(z) = (F (x)y∗ + xd(y))z∗ + xyd(z) = F (x)y∗z∗ + xd(y)z∗ + xyd(z). On the other hand, F (xyz) = F (x)(yz)∗ + xd(yz) = F (x)z∗y∗ + x(d(y)z∗ + yd(z)) = F (x)z∗y∗ + xd(y)z∗ + xyd(z). Combining the both expressions for F (xyz), we get F (x)y∗z∗ = F (x)z∗y∗ for allx, y, z ∈ N. (1) Replacing y and z by y∗ and z∗, respectively, in (1), we obtain F (x)yz = F (x)zy for allx, y, z ∈ N. (2) Taking yt instead of y in (2), where t ∈ N, and using it again we arrive at F (x)yzt = F (x)ytz for allx, y, z, t ∈ N. (3) So that, F (x)y[z, t] = 0 for allx, y, z, t ∈ N. (4) Replacing z and t by t∗ and z∗, respectively, in (4), we obtain F (x)y[t∗, z∗] = 0 for allx, y, z, t ∈ N. (5) Since [t∗, z∗] = [z, t]∗, equation (5) can be written as F (x)y[z, t]∗ = 0 for allx, y, z, t ∈ N. (6) From (4) and (6), we őnd that F (x)N [z, t] = F (x)N [z, t]∗ = {0} for all x, z, t ∈ N. (7) In view of the ∗-primeness of N , (7) shows that F (x) = 0 or [z, t] = 0 for all x, z, t ∈ N. Since F ̸= 0, we conclude that [z, t] = 0 for z, t ∈ N . And therefore, the multiplicative law of N is commutative. Now, let x, y, z ∈ N . Then we 284 Commutativity criteria for 3-prime near-rings have (x+ x)(y+ z) = (y+ z)(x+x). It follows that (x+ x)y+ (x+x)z = (y+z)x+(y+z)x for all x, y, z ∈ N. The previous relation can be rewritten as y(x+ x) + z(x+ x) = x(y + z) + x(y + z). After simplifying, we have yx+ zx = xz + xy which implies that x((y + z)− (z + y)) = 0 for all x, y, z ∈ N. (8) Replacing y and z by y∗ and z∗, respectively, in (8), we arrive at x((y + z)− (z + y))∗ = 0 for all x, y, z ∈ N. (9) Now, comparing the identities (8) and (9), we őnd that x((y + z)− (z + y)) = x((y + z)− (z + y))∗ = 0 for all x, y, z ∈ N. Next putting xt, where t ∈ N , in place of x, we obtain xt((y + z)− (z + y)) = xt((y + z)− (z + y))∗ = 0 for all x, y, z, t ∈ N. It follows that xN((y + z)− (z + y)) = xN((y + z)− (z + y))∗ = {0} for all x, y, z ∈ N. (10) In the light of the ∗-primeness of N and N ̸= {0}, (10) shows that (y + z)− (z + y) = 0 for all y, z ∈ N , i.e, (N,+) is abelian. Consequently, N is a commutative ring. This completes the proof of our theorem. The following example proves that the hypothesis of ∗-primeness in the previous Theorem is not superŕuous. Example 1. Let N = {( 0 0 x 0 0 y 0 0 0 ) | 0, x, y ∈ S } , where S is a zero- symmetric left near-ring such that the addition in S is not commutative. Of course N with matrix addition and matrix multiplication is a left near-ring. Deőne mappings ∗, d, F : N → N such that ( 0 0 x 0 0 y 0 0 0 ) ∗ = ( 0 0 y 0 0 x 0 0 0 ) , d ( 0 0 x 0 0 y 0 0 0 ) = ( 0 0 x 0 0 0 0 0 0 ) and F ( 0 0 x 0 0 y 0 0 0 ) = ( 0 0 0 0 0 y 0 0 0 ) . It is clear that N is not ∗-prime near-ring and F is a nonzero ∗-generalized derivation associated with a ∗-derivation d. But, since the addition in N is not commutative, N cannot be a commutative ring. A. Raji 285 Theorem 2. Let N be a 3-semiprime near-ring. If N admits a nonzero ∗-generalized derivation F , then N contains a nonzero commutative ring under the operations of N. Proof. Given that there exists a ∗-generalized derivation F of N . Arguing as in the proof of Theorem 1, we have relation (4) F (x)y[z, t] = 0 for all x, y, z, t ∈ N. (11) Taking z = F (x) and y = ty in (11) and applying ∗, we őnd that [F (x), t]∗y∗t∗(F (x))∗ = 0 for all x, y, t ∈ N. (12) On the other hand, left multiplying (11) by t and replacing z by F (x), we obtain tF (x)y[F (x), t] = 0 for all x, y, t ∈ N. Now, applying ∗ for this relation, we get [F (x), t]∗y∗(F (x))∗t∗ = 0 for all x, y, t ∈ N. (13) Combining the identities (12) and (13), we conclude that [F (x), t]∗y∗[t∗, (F (x))∗] = 0 for all x, y, t ∈ N, which means that [F (x), t]∗y∗[F (x), t]∗ = 0 for all x, y, t ∈ N. (14) Once again applying ∗ to (14), we obtain [F (x), t]y[F (x), t] = 0 for all x, y, t ∈ N. Accordingly, [F (x), t]N [F (x), t] = {0} for all x, t ∈ N. In view of the semiprimeness of N , the last relation assures that [F (x), t] = 0 for all x, t ∈ N ; in other words F (N) ⊆ Z(N). As F ̸= 0, then there is an element x0 ∈ N such that F (x0) ̸= 0. Now let H the subset of N be deőned by: H = {F (x0)r | r ∈ N}. Our goal is to show that H is a commutative ring included in N . Firstly, we have H ̸= {0}. Indeed, suppose that F (x0)r = 0 for all r ∈ N . Right 286 Commutativity criteria for 3-prime near-rings multiplying by F (x0) we get F (x0)rF (x0) = 0 for all r ∈ N . Using the semiprimeness of N , we őnd that F (x0) = 0; a contradiction. Secondly, showing that (H,+, .) is a semiprime left near-ring. As N is a left near-ring and F (x0) ∈ Z(N), then with a simple calculation, it is easy to see that H is a nonzero left near-ring. Next, we show that H is a semiprime near-ring. Indeed, let a ∈ N such that F (x0)aHF (x0)a = {0}. Then F (x0)aF (x0)rF (x0)a = 0 for all r ∈ N. (15) Right multiplying (15) by F (x0) and using the fact that F (x0) ∈ Z(N), we obtain F (x0)aF (x0)rF (x0)aF (x0) = ( ( F (x0) )2 a ) r ( ( F (x0) )2 a ) = 0 for all r ∈ N . It follows that ( ( F (x0) )2 a ) N ( ( F (x0) )2 a ) = {0}. In view of the semiprimeness of N , the preceding equation shows that ( F (x0) )2 a = 0 . Once again left multiplying this equation by ar, where r ∈ N , we get F (x0)arF (x0)a = 0 for all r ∈ N. (16) Since N is a semiprime near-ring, (16) implies that F (x0)a = 0. And therefore, H is a 3-semiprime left near-ring. Now, returning to equation (2) of the previous theorem, this equation remains valid in this theorem. So we have F (x)[y, z] = 0 for all x, y, z ∈ N . Taking x = x0 and left multiplying by r, we obtain F (x0)r[y, z] = 0 for all r, y, z ∈ N . Setting t = F (x0)r, where r ∈ N , then the last relation yields t[y, z] = 0 for all t ∈ H, y, z ∈ N . In particular, for y, z ∈ H, we have t[y, z] = 0 for all t, y, z ∈ H which implies that [y, z]t[y, z] = 0 for all t, y, z ∈ H. Accordingly, [y, z]H[y, z] = {0} for all y, z ∈ H. Using the fact that H is a 3-semiprime near-ring, the last equation shows that [y, z] = 0 for all y, z ∈ H. Hence, the multiplicative law of H is commutative; thereby, for all x, y, z ∈ H we have (x+x)(y+z) = (y+z)(x+ A. Raji 287 x). Arguing as in the proof of Theorem 1, we arrive at x((y+z)−(z+y)) = 0 for all x, y, z ∈ H. Replacing x by ((y + z)− (z + y))x, we get ((y + z)− (z + y))x((y + z)− (z + y)) = 0 for all x, y, z ∈ H. Consequently, ((y+z)− (z+y))H((y+z)− (z+y)) = {0} for all y, z ∈ H and semiprimeness of H yields that (y + z)− (z + y) = 0 for all y, z ∈ H . So, we conclude that H is a commutative ring and hence N contains a nonzero commutative ring. Then, the Theorem is proved. Theorem 3. Let N be a 3-semiprime near-ring and F be a ∗-generalized derivation of N associated with a ∗-derivation d which commutes with ∗. Then F must be a left ∗-multiplier if F 2 = 0. Proof. By the hypothesis, we have F 2(xy) = F (x)d(y∗) + F (x)(d(y))∗ + xd2(y) = 0 for all x, y ∈ N . Replacing x by F (x) in the preceding equation, we obtain F (x)d2(y) = 0 for all x, y ∈ N. (17) By deőning F , we have F (xyz∗) = F (xy)z + xyd(z∗) and F (xyz∗) = F (x)zy∗ + xd(y)z + xyd(z∗) for all x, y, z ∈ N . Comparing the above expressions of F (xyz∗), we őnd that F (xy)z = F (x)zy∗ + xd(y)z for all x, y, z ∈ N . Now, taking xt instead of x in (17) and applying the last result, we arrive at xd(t)d2(y) = 0 for all x, t, y ∈ N. Writing d(y) in the place of t and using ([2], Theorem 3.9), we get d2(y)xd2(y) = 0 for all x, y ∈ N . By the semiprimeness of N , we con- clude that d2 = 0, furthermore d = 0 by ([3], Lemma 2.5). And there- fore, F (xy) = F (x)y∗ for all x, y ∈ N which means that F is a left ∗-multiplier. 3. Conditions involving generalized semiderivations In this section, our near-rings are right near-rings. In order to prove our main theorems, we shall need the following lemmas. Lemma 1. Let N be a 3-prime near-ring. (i) ([4], Lemma 1.2 (iii)) If z ∈ Z(N)\{0} and xz ∈ Z(N), then x ∈ Z(N). (ii) ([4], Lemma 1.5) If N ⊆ Z(N), then N is a commutative ring. 288 Commutativity criteria for 3-prime near-rings Lemma 2. Let N be an arbitrary right near-ring admitting a semideriva- tion d associated with a function g. Then N is a zero-symmetric near-ring. Moreover, if N is 3-prime and d ̸= 0, then g(0) = 0. Proof. Since N is a right near-ring, we have 0 · x = 0 for all x ∈ N . Now, let d be a semiderivation of N associated with a function g and let x, y be two arbitrary elements of N , by deőning the property of d, we have d(x · 0) = xd(0) + d(x)g(0) = x · 0 + d(x)g(0) = g(x)d(0) + d(x) · 0 = g(x) · 0 + d(x) · 0 and d((x · 0) · y) = x · 0 · d(y) + d(x · 0)g(y) = x · 0 + d(x · 0)g(y) = x · 0 + (x · 0 + d(x)g(0))g(y) = x · 0 + (g(x) · 0 + d(x) · 0)g(y). So, d((x · 0) · y) = x · 0+ x · 0 · g(y) + d(x)g(0)g(y) = x · 0+ g(x) · 0 · g(y) + d(x) · 0 · g(y) which implies that x · 0 + d(x)g(0)g(y) = g(x) · 0 + d(x) · 0. As g(x) · 0 + d(x) · 0 = x · 0 + d(x)g(0) by deőning d(x · 0), and after simplifying, the preceding result shows that d(x)g(0)g(y) = d(x)g(0) for all x, y ∈ N. On the other hand, we have d(x · (0 · y)) = xd(0 · y) + d(x)g(0 · y) = x · 0 + d(x)g(0) for all x, y ∈ N. From the preceding expressions of d(x ·0 ·y), we őnd that x ·0+d(x)g(0) = x · 0 + x · 0 + d(x)g(0)g(y) for all x, y ∈ N. After simplifying, the latter equation assures that x · 0 = 0 for all x ∈ N. Consequently, N is a zero- symmetric near-ring. Assume now that N is 3-prime and d ≠ 0, by applying the last result, we get d(x·0) = 0 = x·0+d(x)g(0) = d(x)g(0) for all x ∈ N. Replacing x by xt gives d(xt)g(0) = 0 = ( g(x)d(t) + d(x)t ) g(0) for all x, t ∈ N , which implies that d(x)tg(0) = 0 for all x, t ∈ N. Accordingly, d(x)Ng(0) = {0} for all x ∈ N . Since N is 3-prime and d ̸= 0, we conclude that g(0) = 0. In right near-ring N , left distributive property does not hold in general. However, the following Lemma has its own signiőcance. A. Raji 289 Lemma 3. Let N be a near-ring admitting a semiderivation d associated with a function g such that g(xy) = g(x)g(y) for all x, y ∈ N . Then N satisőes the following partial distributive law: x(yd(z) + d(y)g(z)) = xyd(z) + xd(y)g(z) for all x, y, z ∈ N. Proof. We have d((xy)z) = xyd(z) + d(xy)g(z) = xyd(z) + xd(y)g(z) + d(x)g(y)g(z) and d(x(yz)) = xd(yz) + d(x)g(yz) = x(yd(z) + d(y)g(z)) + d(x)g(yz). Comparing these two equations gives the desired result. Lemma 4. Let N be a near-ring. If N admits a semiderivation d associ- ated with an onto map g, then d(z) ∈ Z(N) for all z ∈ Z(N). Proof. Calculate d(xz) and d(zx) where x ∈ N, z ∈ Z(N) and compare. Theorem 4. Let N be a 2-torsion free 3-prime near-ring admitting a generalized semiderivation F associated with a nonzero semiderivation d which is associated with an onto map g such that g(xy) = g(x)g(y) for all x, y ∈ N . If F ([x, y]) = 0 for all x, y ∈ N , then N is a commutative ring. Proof. By the hypothesis given, we have F (xy) = F (yx) for all x, y ∈ N , hence F (x)y + g(x)d(y) = d(y)g(x) + yF (x) for all x, y ∈ N. Replacing x by [r, s] in the previous equation, we get g([r, s])d(y) = d(y)g([r, s]) for all y, r, s ∈ N. (18) Substituting yd(t) for y in (18) and invoking Lemma 3, we obtain g([r, s])yd2(t) + g([r, s])d(y)g(d(t)) = yd2(t)g([r, s]) + d(y)g(d(t))g([r, s]) for all y, r, s, t ∈ N. Taking into account that g(d(t)) = d(g(t)) for all t ∈ N and using (18), we őnd that g([r, s])yd2(t) = yd2(t)g([r, s]) for all y, r, s, t ∈ N. (19) Replacing y by yn in (19) and using (19) again, we get g([r, s])ynd2(t) = ynd2(t)g([r, s]) = y ( nd2(t)g([r, s]) ) = yg([r, s])nd2(t) for all y, n, r, s, t ∈ N, 290 Commutativity criteria for 3-prime near-rings which leads to [g([r, s]), y]Nd2(t) = {0} for all y, r, s, t ∈ N. (20) By the 3-primeness of N , equation (20) assures that d2(t) = 0 or g([r, s]) ∈ Z(N) for all r, s, t ∈ N. (21) Suppose that d2(t) = 0 for all t ∈ N . In particular, we have 0 = d2(tu) = d(td(u) + d(t)g(u)) = 2d(t)d(g(u)) for all t, u ∈ N. In view of the 2-torsion freeness of N , the above relation implies that d(t)d(g(u)) = 0 for all t, u ∈ N . Now, replacing t by xt, where x ∈ N , in the preceding equation, we őnd that d(x)td(g(u)) = 0 for all x, t, u ∈ N . It follows that d(x)Nd(g(u)) = {0} for all x, u ∈ N which, as N is 3-prime and d ≠ 0, implies that d(g(u)) = 0 = g(d(u)) for all u ∈ N . Now, by the deőning property of d, we have d(vd(u)) = vd2(u) + d(v)g(d(u)) = g(v)d2(u) + d(v)d(u) for all u, v ∈ N. Comparing these two expressions for d(vd(u)) gives d(v)d(u) = 0 for all u, v ∈ N. Taking v = vt and using the same arguments as used above, we conclude that d = 0. But this contradicts our assumption that d ̸= 0; hence, equation (21) forces g([r, s]) ∈ Z(N) for all r, s ∈ N . Replacing s by sr in the previous result and noting that [r, sr] = [r, s]r, we obtain g([r, sr]) = g([r, s]r) = g([r, s])g(r) ∈ Z(N) for all r, s ∈ N. According to Lemma 1(i), we conclude that g([r, s]) = 0 or g(r) ∈ Z(N) for all r, s ∈ N. (22) Suppose there exist two elements r, s ∈ N such that g([r, s]) = 0. In this case, using Lemma 2 and g is onto, we őnd that [r, s] = 0 which means that rs = sr. And therefore g(rs) = g(sr), hence g(r)g(s) = g(s)g(r). So, equation (22) reduces to g(r)g(s) = g(s)g(r) or g(r) ∈ Z(N) for all r, s ∈ N. (23) A. Raji 291 But it is clear that g(r) ∈ Z(N) implies g(r)g(s) = g(s)g(r) for all s ∈ N . Consequently, (23) yields g(r)g(s) = g(s)g(r) for all r, s ∈ N . Since g is onto, the latter equation shows that rs = sr for all r, s ∈ N. Which means that N ⊆ Z(N) and our result follows by Lemma 1(ii). The following result proves that the conclusion of the previous Theorem is not valid if we replace the product [x, y] by x ◦ y. Indeed, Theorem 5. Let N be a 2-torsion free 3-prime near-ring. There is no nonzero generalized semiderivation F associated with a semiderivation d which is associated with an onto map g such that g(xy) = g(x)g(y) for all x, y ∈ N satisőes F (x ◦ y) = 0 for all x, y ∈ N. Proof. Suppose that F (x ◦ y) = 0 for all x, y ∈ N. (24) It follows that F (xy) + F (yx) = 0 for all x, y ∈ N. By the deőning property of F , we get F (x)y + g(x)d(y) + d(y)g(x) + yF (x) = 0 for all x, y ∈ N. (25) Substituting u ◦ v for x in (25) and invoking (24), we obtain g(u ◦ v)d(y) + d(y)g(u ◦ v) = 0 for all y, u, v ∈ N. (26) Taking yt instead of y in (26) and using Lemma 3, we get g(u ◦ v)yd(t) + g(u ◦ v)d(y)g(t) + d(y)g(t)g(u ◦ v) + yd(t)g(u ◦ v) = 0 for all u, v, y, t ∈ N. Replacing t by u ◦ v and using (26), we arrive at g(u ◦ v)yd(u ◦ v) = −yd(u ◦ v)g(u ◦ v) for all u, v, y ∈ N. (27) Substituting yt for y in (27), we őnd that g(u ◦ v)ytd(u ◦ v) = −ytd(u ◦ v)g(u ◦ v) = (−y)(td(u ◦ v)g(u ◦ v)) = (−y)(−g(u ◦ v)td(u ◦ v)) = (−y)(−g(u ◦ v))td(u ◦ v) for all u, v, y, t ∈ N. 292 Commutativity criteria for 3-prime near-rings Hence, ( g(u ◦ v)y − (−y)(−g(u ◦ v)) ) td(u ◦ v) = 0 for all u, v, y, t ∈ N. (28) Therefore, (28) can be rewritten as ( − (−g(u ◦ v))y+ y(−g(u ◦ v)) ) Nd(u ◦ v) = {0} for all u, v, y ∈ N. (29) By 3-primeness of N , equation (29) implies that −g(u ◦ v) ∈ Z(N) or d(u ◦ v) = 0 for all u, v ∈ N. (30) So, −g(u ◦ v) ∈ Z(N) or g(d(u ◦ v)) = 0 for all u, v ∈ N. (31) Suppose there are two elements u0 and v0 of N such that −g(u0 ◦ v0) ∈ Z(N). If d(Z(N)) = {0}, then 0 = d(−g(u0 ◦ v0)) = −d(g(u0 ◦ v0)) = d(g(u0 ◦ v0)) which implies that g(d(u0 ◦ v0)) = 0. On the other hand, if d(Z(N)) ̸= {0}, in this case, returning to (26) and replacing y by an element z0 ∈ Z(N) such that d(z0) ̸= 0, also taking u = u0 and v = v0, according to Lemma 4, we obtain 2g(u0 ◦ v0)d(z0) = 0. By 2-torsion freeness the latter relation shows that g(u0 ◦ v0)d(z0) = 0 (32) Right multiplying (32) by n, where n ∈ N , we obtain g(u0 ◦ v0)nd(z0) = 0 for all n ∈ N. Which implies that g(u0 ◦ v0)Nd(z0) = {0}. In view of the 3-primeness of N and d(z0) ̸= 0, we conclude that g(u0◦v0) = 0, hence d(g(u0 ◦v0)) = 0 which yields g(d(u0 ◦v0)) = 0. Thus, in the both cases, i.e d(Z(N)) = {0} or d(Z(N)) ̸= {0}, we őnd that g(d(u0 ◦v0)) = 0. Consequently, (31) reduces to g(d(u ◦ v)) = 0 for all u, v ∈ N. According to Lemma 2 and g is onto, the last relation yields d(u ◦ v) = 0 for all u, v ∈ N. (33) A. Raji 293 Taking vu instead of v in (33) and using (33), we get (u ◦ v)d(u) = 0 for all u, v ∈ N that is, uvd(u) = −vud(u) for all u, v ∈ N. Next putting vt, where t ∈ N , in place of v we arrive at uvtd(u) = (−v)(−u)td(u) for all u, v, t ∈ N. It follows that (uv + v(−u))td(u) = 0 for all u, v, t ∈ N. Taking −u instead of u, hence the last relation can be rewritten as (−uv + vu)Nd(−u) = {0} for all u, v ∈ N. Which, in the light of the primeness of N , yields u ∈ Z(N) or d(u) = 0 for all u ∈ N. (34) Let u0 ∈ Z(N), from (33) and 2-torsion freeness, we have d(u0 ◦ v) = 0 = d(u0v) for all v ∈ N . By deőning d, we get g(u0)d(v) + d(u0)v = 0 for all v ∈ N . Replacing v by vu0 in the last result, we őnd that d(u0)vu0 = 0 for all v ∈ N . Once again using the 3-primeness of N , we conclude that d(u0) = 0 or u0 = 0, given that d(u0) = 0. And therefore, (34) proves that d(u) = 0 for all u ∈ N . Our goal in what follows is to show that d = 0 implies F = 0. Let x, y ∈ N , by deőning F and our hypothesis d = 0, equation (24) yields F (x◦y) = 0 = F (xy)+F (yx) = xF (y)+yF (x) for all x, y ∈ N . Replacing x by x ◦ t, we get (x ◦ t)F (y) = 0 for all x, y, t ∈ N , which means that xtF (y) = −txF (y) for all x, y, t ∈ N. Taking tm instead of t in the last equation, where m ∈ N , and using the same equation we arrive at xtmF (y) = (−t)(−x)mF (y) for all x, y, t,m ∈ N. It follows that (xt+ t(−x))NF (y) = {0} for all x, y, t ∈ N. 294 Commutativity criteria for 3-prime near-rings Putting −x instead of x, we get (−xt+ tx)NF (y) = {0} for all x, y, t ∈ N. In the light of the 3-primeness of N , we conclude that N ⊆ Z(N) or F = 0. But if N ⊆ Z(N), N is a commutative ring by Lemma 1(ii). In this case, returning to (24) and using the fact that N is 2-torsion free, we obtain F (xy) = 0 = xF (y) for all x, y ∈ N . Replacing x by xt, we get xtF (y) = 0 for all x, y, t ∈ N . Once again N is 3-prime, the last expression yields F = 0, which is contrary to our hypothesis. This completes the proof of our Theorem. Theorem 6. Let N be a 2-torsion free 3-prime near-ring admitting a generalized semiderivation F associated with a nonzero semiderivation d which is associated with an automorphism map g such that F ([x, y]) = [x, y] for all x, y ∈ N , then N is a commutative ring. Proof. Assume that F ([x, y]) = [x, y] for all x, y ∈ N. (35) Replacing y by yx in (35), we get F ([x, y])x+ g([x, y])d(x) = [x, y]x for all x, y ∈ N. (36) In view of (35) and g is an homomorphism, equation (36) can be rewritten as g(x)g(y)d(x) = g(y)g(x)d(x) for all x, y ∈ N. Once again, since g is onto, the last equation yields g(x)yd(x) = yg(x)d(x) for all x, y ∈ N. (37) Taking yt instead of y in (37) and using (37) again, we őnd that g(x)ytd(x) = ytg(x)d(x) = y(tg(x)d(x)) = yg(x)td(x) for all x, y, t ∈ N implying that (g(x)y − yg(x))td(x) = 0 for all x, y, t ∈ N A. Raji 295 that is, [g(x), y]Nd(x) = {0} for all x, y ∈ N. (38) By the use of 3-primeness of N , (38) yields g(x) ∈ Z(N) or d(x) = 0 for all x ∈ N (39) in the latter case, we see that if d(x) = 0, then g(d(x)) = d(g(x)) = 0. So, (39) proves that either g(x) ∈ Z(N) or d(g(x)) = 0 for all x ∈ N. Since g is onto, the above relation shows that x ∈ Z(N) or d(x) = 0 for all x ∈ N . And according to Lemma 4 we conclude that d(x) ∈ Z(N) for all x ∈ N . Replacing x by xy, gives d(xy) = xd(y) + d(x)g(y) ∈ Z(N) for all x, y ∈ N. (40) Using Lemma 3, (40) implies that x2d(x) + xd(x)g(y) = x2d(x) + d(x)g(y)x for all x, y ∈ N, this is reduced to [g(y), x]Nd(x) = {0} for all x, y ∈ N. (41) Since N is 3-prime and g is onto, (41) shows that x ∈ Z(N) or d(x) = 0 for all x ∈ N. (42) If there is an element x0 of N such that d(x0) = 0, according to the equation (40), we obtain x0d(y) ∈ Z(N) for all y ∈ N. (43) Since d ̸= 0, then Lemma 1(i) assures that x0 ∈ Z(N), and therefore (42) reduces to x ∈ Z(N) for all x ∈ N . The Lemma 1(ii) demonstrates that N is a commutative ring. Theorem 7. Let N be a 2-torsion free 3-prime near-ring. There is no generalized semiderivation F associated with a nonzero semiderivation d which is associated with an automorphism map g such that F (x◦y) = x◦y for all x, y ∈ N . 296 Commutativity criteria for 3-prime near-rings Proof. Suppose that there is F which indicates the following F (x ◦ y) = x ◦ y for all x, y ∈ N. (44) Substituting yx for y in (44), because of x ◦ yx = (x ◦ y)x, we obtain F ((x ◦ y)x) = (x ◦ y)x for all x, y ∈ N. By deőning F , we get F (x ◦ y)x+ g(x ◦ y)d(x) = (x ◦ y)x for all x, y ∈ N. (45) From (44) and (45), we őnd that g(x ◦ y)d(x) = 0 for all x, y ∈ N. As g is an homomorphism, we have g(x)g(y)d(x) = −g(y)g(x)d(x) for all x, y ∈ N. Since g is onto, the last equation shows that g(x)yd(x) = −yg(x)d(x) for all x, y ∈ N. (46) Replacing y by yt in (46) and using (46) again, we have g(x)ytd(x) = −ytg(x)d(x) = (−y)(tg(x)d(x)) = (−y)(−g(x)td(x)) = (−y)(−g(x))td(x) for all x, y, t ∈ N. But since g is an additive map, we have −g(x) = g(−x) and g(x)ytd(x) = (−y)g(−x)td(x) for all x, y, t ∈ N , which can be rewritten as (−g(−x)y + yg(−x))Nd(x) = {0} for all x, y ∈ N. Taking −x instead of x in the latter relation and using the 3-primeness of N , we arrive at g(x) ∈ Z(N) or d(x) = 0 for all x ∈ N. To complete the proof, we only need to consider the same arguments as used after (39) in the proof of Theorem 6, we arrive at a conclusion N is A. Raji 297 a commutative ring. Now, returning to the assumptions of theorem, we obtain F (xy) = F (x)y + g(x)d(y) = xy for all x, y ∈ N. Putting xz instead of x, we arrive at g(x)g(z)d(y) = 0 for all x, y, z ∈ N. (47) Taking into account that g is onto, (47) yields xNd(y) = {0} for all x, y ∈ N. In the light of the 3-primeness of N , the laste equation forces that d = 0, which is a contradiction. The following example shows that the condition of 3-primeness in the hypothesis of Theorems 4, 5, 6 and 7 is crucial. Example 2. Let S be a noncommutative 2-torsion free zero-symmetric right near-ring. Let us deőne N,F, d, g : N → N by: N = {( 0 x y 0 0 0 0 0 0 ) | 0, x, y ∈ S } , F ( 0 x y 0 0 0 0 0 0 ) = ( 0 x 0 0 0 0 0 0 0 ) , d ( 0 x y 0 0 0 0 0 0 ) = ( 0 y x 0 0 0 0 0 0 ) and g = d. It can be checked that N with matrix addition and matrix multiplication is not a 3-prime right near-ring and F is a nonzero generalized semiderivation of N associated with a nonzero semiderivation d which is associated with the automorphism map g such that the following situations hold: (i) F ([A,B]) = 0, (ii) F (A◦B) = 0, (iii) F ([A,B]) = [A,B], (iv) F (A◦B) = A ◦B for all A,B ∈ N . However, N is not a commutative ring. References [1] S. Ali, On generalized ∗-derivations in ∗-rings, Palestine J. Math. 1 (2012), 32-37. [2] M. Ashraf and M. A. Siddeeque, On ∗-derivations in near-rings with involution, J. Adv. Res. Pure Math. 6 (2) (2014), 1-12. [3] H. E. Bell and G. Mason, On derivations in near-rings, (G. Betsch editor), North- Holland/ American Elsevier, Amsterdam 137 (1987), 31-35. [4] H. E. Bell, On derivations in near-rings, II, Kluwer Academic Publishers Nether- lands (1997), 191-197. 298 Commutativity criteria for 3-prime near-rings [5] A. Boua and L. Oukhtite, Semiderivations satisfying certain algebraic identities on prime near-rings, Asian Eur. J. Math. 6 (3) (2013), 1350043 (8 pages). [6] M. Bresar, J. Vukman, On some additive mappings in rings with involution, Aequat. Math. 38 (1989), 178-185. [7] Y. Fong, Derivation in near-ring theory, Contemp. Mathematics 264 (2000), 91-94. [8] L. Oukhtite and S. Salhi, On commutativity of σ-prime rings, Glasnik Mathematicki 41 (1) (2006), 57-64. [9] G. Pilz, Near-Rings. 2nd Edition, North Holland /American Elsevier, Amsterdam, 1983. [10] X. K. Wang, Derivations in prime near-rings, Proc. Amer. Math. Soc. 121 (1994), 361-366. Contact information Abderrahmane Raji LMACS Laboratory Faculty of Sciences and Technology Sultan Moulay Slimane University P.O.Box 523, 23000, Beni Mellal, Morocco E-Mail(s): rajiabd2@gmail.com Received by the editors: 18.08.2019 and in őnal form 26.04.2021. mailto:rajiabd2@gmail.com A. Raji