We generalize the construction of the formal ball model for metric spaces due to A. Edalat and R. Heckmann to obtain computational models for separated Q-categories. We fully describe (a) Yoneda complete and (b) continuous Yoneda complete Q-categories via their formal ball models. Our results yield solutions to two open problems in the theory of quasi-metric spaces: we show that (a) a quasi-met...

Let G = (V, E) be a connected graph and let d(u, v) denote the distance between vertices u, v ∈ V. A metric basis for G is a set B ⊆ V of minimum cardinality such that no two vertices of G have the same distances to all points of B. The cardinality of a metric basis of G is called the metric dimension of G, denoted by dim(G). In this paper we determine the metric dimension of the circulant grap...

Let (X; ) be a metric space, let (K(X); e ) denote the space of nonempty compact subsets of X with the Hausdor metric, and let E X. The purpose of this paper is to investigate the relationships between the entropy dimensions of E and of K(E). 1 The de nition and properties of the entropy indices. Given a separable metric space (X; ), let K(X) denote the set of non-empty compact subsets of X . D...

We unify the concepts of G-metric, metric-like, and b-metric to define new notion of generalized b-metric-like space and discuss its topological and structural properties. In addition, certain fixed point theorems for two classes of G-α -admissible contractive mappings in such spaces are obtained and some new fixed point results are derived in corresponding partially ordered space. Moreover, so...

Azam et al. (2011), introduce the notion of complex valued metric spaces and obtained common fixed point result for mappings in the context of complex valued metric spaces. Rao et al. (2013) introduce the notion of complex valued b-metric spaces. In this paper, we generalize the results of Azam et al. (2011), and Bhatt et al. (2011), by improving the conditions of contraction to establish the e...

The existing literature of fixed point theory contains many results enunciating fixed point theorems for self-mappings in metric and Banach spaces. Recently, Huang and Zhang [4] introduced the concept of cone metric spaces which generalized the concept of the metric spaces, replacing the set of real numbers by an ordered Banach space, and obtained some fixed point theorems for mapping satisfyin...

The proper Euclidean geometry is considered to be metric space and described in terms of only metric and finite metric subspaces (σ-immanent description). Constructing the geometry, one does not use topology and topological properties. For instance, the straight, passing through points A and B, is defined as a set of such points R that the area S(A,B,R) of triangle ABR vanishes. The triangle ar...