the certainty assumption that is used in economic analysis, althouth is easier in analysis, may be but not logical because in most projects time is playing a key role. in this time horizon the amount of income and future costs affecting by factors that are not managable by investors and can not to be forecasted. therefore in practice usually there is a gap between forecased and real variables. ...

In this paper, a condition which ensures the existence of fuzzy simply open sets in $P$- space is obtained. It established that disjoint $G_{\delta}$-sets $P$-space are cs dense sets. A for strongly irresolvable and globally disconnected to become hyperconnected D-Baire space. obtained extremally disconnected, semi-$P$ does not have $G_{\delta}$-sets.

we present a methodology for characterization and an approach for computing the solutions of fuzzy linear systems with lr fuzzy variables. as solutions, notions of exact and approximate solutions are considered. we transform the fuzzy linear system into a corresponding linear crisp system and a constrained least squares problem. if the corresponding crisp system is incompatible, then the fuzzy ...