Weakly primary semi-ideals in posets

One of the main goals of science and engineering is to avail human beings cull the maximum propitious decisions. To make these decisions, we need to ken human being's predictions, feasible outcomes of various decisions, and since information is never absolutely precise and accurate, we need to withal information about the degree of certainty. All these types of information will lead to partial orders. A partially ordered set (or poset) theory deals with partial orders and plays a major role in real life. It has wide range of applications in various disciplines such as computer science, engineering, medical field, science, modeling spatial relationship in geographic information systems (GIS), physics and so on. In this paper, we mainly focus on weakly primary semi-ideal of a poset. We introduce the concepts of weakly primary semi-ideal and weakly Q-primary semi-ideal for some prime Q of a poset P and characterize weakly primary semi-ideals of P in terms of prime and primary semi-ideals of P. We provide a counter-example for the existence of weakly primary semi-ideal of P which is not a primary semi-ideal of P. We found an equivalent assertion of primary (respy., weakly primary) semi-ideal r(K) for a semi-ideal K of P. Moreover, we introduce the notion of direct product of weakly primary semi-ideal of P and describe its characteristics.