this paper is devoted to the concepts of fuzzy upper and fuzzy lower contra-continuous multifunctions and also some characterizations of them are considered.

An SLn-character of a groupG is the trace of an SLn-representation of G.We show that all algebraic relations between SLn-characters of G can be visualized as relations between graphs (resembling Feynman diagrams) in any topological space X, with π1(X) = G. We also show that all such relations are implied by a single local relation between graphs. In this way, we provide a topological approach t...

We determine the topological Euler number of certain moduli space of 1-dimensional closed subschemes in a smooth projective variety which admits a Zariski-locally trivial fibration with 1-dimensional fibers. The main approach is to use virtual Hodge polynomials and torus actions. The results might shed some light on the corresponding Donaldson-Thomas invariants.

in 1997, fang proposed the concept of boundedness of $l$-fuzzy setsin $l$-topological vector spaces. since then, this concept has beenwidely accepted and adopted in the literature. in this paper,several characterizations of bounded $l$-fuzzy sets in$l$-topological vector spaces are obtained and some properties ofbounded $l$-fuzzy sets are investigated.

0 Introduction In this paper we study, for a certain type of topological rings A, the topological space Cont A of all equivalence classes of continuous valuations of A. The space ContA is defined as follows. Let v: A-+Fw{0} be a valuation of A, where F is an ordered multiplicative group generated by im(v)\{0}. On Fw [0} we introduce the topology such that U _~ F ~ {0} is open iff 0 q~ U or {xeF...

Stepr¯ ans provided a characterization of βN \ N in the ℵ 2-Cohen model that is much in the spirit of Parovičenko's characterization of this space under CH. A variety of the topological results established in the Cohen model can be deduced directly from the properties of βN \ N or P(N)/fin that feature in Stepr¯ ans' result.

Steprāns provided a characterization of βN \ N in the א2-Cohen model that is much in the spirit of Parovičenko’s characterization of this space under CH. A variety of the topological results established in the Cohen model can be deduced directly from the properties of βN\N or P(N)/fin that feature in Steprāns’ result.

As an alternative to the Khalimsky topology, the topology w on the digital plane Z2 was introduced by the author of this note who also proved a Jordan curve theorem for it. In the present paper, another Jordan curve theorem for the topology w is proved determining a large variety of Jordan curves in the topological space (Z2, w).