ABSTRACT
In 1905, the French mathematician Maurice Fréchet [121, 122] introduced the concept of metric spaces, although the name “metric” is due to Hausdorff [102,157]. In 1934, the Serbian mathematician Duro Kurepa [196], a PhD student of Fréchet, introduced metric spaces in which an ordered vector space is used as the codomain of a metric instead of the set of real numbers. In the literature the metric spaces with vector valued metrics are known under various names such as pseudometric spaces, k-metric spaces, generalized metric spaces, conevalued metric spaces, cone metric spaces, abstract metric spaces and vector valued metric spaces. Fixed point theory in K-metric spaces was developed by A.I.Perov in 1964 [237]. For more details on fixed point theory in K-metric and K-normed spaces, we refer the reader to [291].
