In this paper, the notion of βS∗−compactness is introduced in L−fuzzy topological spaces based on S∗−compactness. A βS∗−compactness L-fuzzy set is S∗−compactness and also β−compactness. Some of its properties are discussed. We give some characterizations of βS∗−compactness in terms of pre-open, regular open and semi-open L−fuzzy set. It is proved that βS∗−compactness is a good extension of β−co...

Let P , where |P| ≥ 2, be a set of points in d-dimensional space with a given metric ρ. For a point p ∈ P , let rp be the distance of p with respect to ρ from its nearest neighbour in P . Let B(p, rp) be the open ball with respect to ρ centered at p and having the radius rp. We define the sphere-of-influence graph (SIG) of P as the intersection graph of the family of sets {B(p, rp) | p ∈ P}. Gi...

In this paper, the notion of maximal m-open set is introduced and itsproperties are investigated. Some results about existence of maximal m-open setsare given. Moreover, the relations between maximal m-open sets in an m-spaceand maximal open sets in the corresponding generated topology are considered.Our results are supported by examples and counterexamples.

A Turing degree a is said to isolate another degree b in the r.e. degrees if and only if a < b and there is no r.e. degree c with a < c < b. In this case b is called an isolated degree and a an isolating degree. There are of course analogous deenitions for any subsets A and B of !. If a isolates b, it follows from the Sacks density theorem that at least one of the two must fail to be r.e. When ...

It is well-known that the Plücker relations generate the ideal of relations of the maximal minors of a generic m× n matrix. In this paper we discuss the relations of t-minors for t < min(m,n). We will exhibit minimal relations in degrees 2 (non-Plücker in general) and 3, and give some evidence for our conjecture that we have found the generating system of the ideal of relations. The approach is...

Let X and Y be Banach spaces, G an open subset of X. If we denote the closure of G by cl(G), let ƒ be a mapping of cl(G) into Y. For X~ Y and ƒ a compact mapping, Leray and Schauder [9] gave a definition of topological degree for mappings of the form ƒ —ƒ on the open set G over a point a of X whenever (I—f)"^) is a compact subset of G. The Leray-Schauder degree for compact displacements is the ...

The path of the rook is a curve γ (possibly, self-intersecting) inside an 8 × 8square. The length of γ should be at least 64 since all squares are visited. Next, I assumed that the rook turned each time by 90 degrees (and never 180). Then the total turn of γ is nπ/2, where n is the number of moves. Thus I traded the original problem for the following one: What is the smallest total turn of a cu...