Hindawi Publishing Corporation International Journal of Mathematics and Mathematical Sciences Volume 2013, Article ID 238490, 6 pages http://dx.doi.org/10.1155/2013/238490 Research Article On Symmetric Left Bi-Derivations in BCI -Algebras G. Muhiuddin, 1 Abdullah M. Al-roqi, 1 Young Bae Jun, 2 and Yilmaz Ceven 3 1 Department of Mathematics, University of Tabuk, Tabuk 71491, Saudi Arabia 2 Department of Mathematics Education (and RINS), Gyeongsang National University, Jinju 660-701, Republic of Korea 3 Department of Mathematics, Faculty of Science, Suleyman Demirel University, 32260 Isparta, Turkey Correspondence should be addressed to G. Muhiuddin; chishtygm@gmail.com Received 15 February 2013; Accepted 30 May 2013 Academic Editor: Aloys Krieg Copyright © 2013 G. Muhiuddin et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te notion of symmetric lef bi-derivation of a BCI -algebra X is introduced, and related properties are investigated. Some results on componentwise regular and d-regular symmetric lef bi-derivations are obtained. Finally, characterizations of a p-semisimple BCI -algebra are explored, and it is proved that, in a p-semisimple BCI -algebra, F is a symmetric lef bi-derivation if and only if it is a symmetric bi-derivation. 1. Introduction BCK-algebras and BCI -algebras are two classes of nonclassi- cal logic algebras which were introduced by Imai and Is´ eki in 1966 [1, 2]. Tey are algebraic formulation of BCK-system and BCI -system in combinatory logic. Later on, the notion of BCI -algebras has been extensively investigated by many researchers (see [36], and references therein). Te notion of a BCI -algebra generalizes the notion of a BCK-algebra in the sense that every BCK-algebra is a BCI -algebra but not vice versa (see [7]). Hence, most of the algebras related to the -norm-based logic such as MTL [8], BL, hoop, MV [9] (i.e lattice implication algebra), and Boolean algebras are extensions of BCK-algebras (i.e. they are subclasses of BCK-algebras) which have a lot of applications in computer science (see [10]). Tis shows that BCK-/BCI -algebras are considerably general structures. Troughout our discussion, will denote a BCI -algebra unless otherwise mentioned. In the year 2004, Jun and Xin [11] applied the notion of derivation in ring and near-ring theory to -algebras, and as a result they introduced a new concept, called a (regular) derivation, in -algebras. Using this concept as defned they investigated some of its properties. Using the notion of a regular derivation, they also established characterizations of a -semisimple - algebra. For a self-map of a -algebra, they defned a - invariant ideal and gave conditions for an ideal to be - invariant. According to Jun and Xin, a self map :→ is called a lef-right derivation (briefy (,)-derivation) of if (∗)=()∗∧∗() holds for all ,∈. Similarly, a self map :→ is called a right-lef derivation (briefy (,)-derivation) of if ( ∗ ) =  ∗ () ∧ () ∗  holds for all , ∈ . Moreover, if is both (,)- and (,)-derivation, it is a derivation on . Afer the work of Jun and Xin [11], many research articles have appeared on the derivations of BCI -algebras and a greater interest has been devoted to the study of derivations in BCI - algebras on various aspects (see [1217]). Inspired by the notions of -derivation [18], lef deriva- tion [19], and symmetric bi-derivations [20, 21] in rings and near-rings theory, many authors have applied these notions in a similar way to the theory of BCI -algebras (see [12, 13, 17]). For instantce in 2005 [17], Zhan and Liu have given the notion of -derivation of BCI -algebras as follows: a self map :→ is said to be a lef-right -derivation or (,)--derivation of if it satisfes the identity ( ∗ ) =  () ∗ () ∧ () ∗  () for all , ∈ . Similarly, a self map :→ is said to be a right- lef -derivation or (,)--derivation of if it satisfes the identity ( ∗ ) = () ∗  () ∧  () ∗ () for all ,∈. Moreover, if is both (,)- and (,)--deriva- tion, it is said that is an -derivation, where is an endomorphism. In the year 2007, Abujabal and Al-Shehri [12] defned and studied the notion of lef derivation of BCI - algebras as follows: a self map :→ is said to be a lef