Hindawi Publishing Corporation Algebra Volume 2013, Article ID 565848, 7 pages http://dx.doi.org/10.1155/2013/565848 Research Article On Ordered Quasi-Gamma-Ideals of Regular Ordered Gamma-Semigroups M. Y. Abbasi and Abul Basar Department of Mathematics, Jamia Millia Islamia, New Delhi 110025, India Correspondence should be addressed to Abul Basar; basar.jmi@gmail.com Received 31 March 2013; Accepted 7 October 2013 Academic Editor: Sorin Dascalescu Copyright © 2013 M. Y. Abbasi and A. Basar. his 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. We introduce the notion of ordered quasi-Γ-ideals of regular ordered Γ-semigroups and study the basic properties of ordered quasi-Γ-ideals of ordered Γ-semigroups. We also characterize regular ordered Γ-semigroups in terms of their ordered quasi-Γ- ideals, ordered right Γ-ideals, and let Γ-ideals. Finally, we have shown that (i) a partially ordered Γ-semigroup is regular if and only if for every ordered bi-Γ-ideal , every ordered Γ-ideal , and every ordered quasi-Γ-ideal , we have ∩∩⊆(ΓΓ] and (ii) a partially ordered Γ-semigroup is regular if and only if for every ordered quasi-Γ-ideal , every ordered let Γ-ideal , and every ordered right-Γ-ideal , we have that ∩∩⊆(ΓΓ]. 1. Introduction Steinfeld [13] introduced the notion of a quasi-ideal for semigroups and rings. Since then, this notion has been the subject of great attention of many researchers and conse- quently a series of interesting results have been published by extending the notion of quasi-ideals to Γ-semigroups, ordered semigroups, ternary semigroups, semirings, Γ-semi- rings, regular rings, near-rings, and many other diferent algebraic structures [415]. It is a widely known fact that the notion of a one-sided ideal of rings and semigroups is a generalization of the notion of an ideal of rings and semigroups and the notion of a quasi- ideal of semigroups and rings is a generalization of a one- sided ideal of semigroups and rings. In fact the concept of ordered semigroups and Γ-semigroups is a generalization of semigroups. Also the ordered Γ-semigroup is a generalization of Γ-semigroups. So the concept of ordered quasi-ideals of ordered semigroups is a generalization of the concept of quasi-ideals of semigroups. In the same way, the notion of an ordered quasi-ideal of ordered semigroups is a general- ization of a one-sided ordered ideal of ordered semigroups. Due to these motivating facts, it is naturally signiicant to generalize the results of semigroups to Γ-semigroups and of Γ-semigroups to ordered Γ-semigroups. In 1998, the concept of an ordered quasi-ideal in ordered semigroups was introduced by Kehayopulu [16]. He stud- ied theory of ordered semigroups based on ordered ideals analogous to the theory of semigroups based on ideals. he concept of po-Γ-semigroup was introduced by Kwon and Lee in 1996 [17] and since then it has been studied by several authors [1822].Our purpose in this paper is to examine many important classical results of ordered quasi- Γ-ideals in ordered Γ-semigroups and then to characterize the regular ordered Γ-semigroups through ordered quasi-Γ- ideals, ordered bi-Γ-ideals and ordered one-sided Γ-ideals. 2. Preliminaries We note here some basic deinitions and results that are relevant for our subsequent results. Let and Γ be two nonempty sets. hen is called a Γ- semigroup if satisies () = () for all , , ∈ and , ∈Γ. A nonempty subset of a Γ-semigroup is called a sub-Γ-semigroup of if ∈ for all , ∈ and ∈Γ. For any nonempty subsets , of , Γ = { : ∈, ∈ and  ∈ Γ}. We also denote {}Γ, Γ{}, and {}Γ{}, respectively, by Γ, Γ, and Γ. Many classical results of semigroups have been generalized and extended to Γ-semigroups [2325]. By an ordered Γ-semigroup