“…This concept is well studied in algebraic structures as well as in ordered structures such as rings, semigroups, lattices, semilattices, posets and qosets; see Anderson et.al. [1], LaGrange [15,16], Lu and Wu [18], Joshi and Khiste [12], Nimbhorkar et.al. [21], Halaš and Jukl [6], Joshi [11], Joshi, Waphare and Pourali [13,14] and Halaš and Länger [9].…”