Definition 4.12: Let (([N.sub.1]), [d.sub.1]) and (([N.sub.2], *), [d.sub.2]) be NT metric spaces
, [mathematical expression not reproducible] and [mathematical expression not reproducible] be NT metric topologies.
They give a unified definition of curvature that applies to a wide class of geometric structures whose geodesics arise from optimal control problems, including Riemannian, sub-Riemannian, Finsler, and sub-Finsler spaces, but pay special attention to the sub-Riemannian (or Carnot-Caratheodory) metric spaces
. Their construction of curvature is direct and naive, they say, similar to the original approach of Riemann.
 Bojor, F, Fixed point theorems for Reich type contraction on metric spaces
with a graph, Nonlinear Anal.
In 2012, Abdeljawad et al.'s paper  contains a study of M-K type coupled fixed point on ordered partial metric spaces
and Chen et al.
An analogue version of Theorem 10 in the setting of the preordered metric spaces
may be stated as follows.
Branciari  introduced the notion of generalized metric spaces
and obtained a generalization of the Banach contraction principle, whereafter many authors proved various fixed point results in such spaces, for example, [2-8] and references therein.
In , the notion of a rectangular metric space
was extended to rectangular partial metric spaces
Recently some authors have introduced some generalizations of metric spaces
in several ways and have studied fixed point problems in these spaces, as well as their applications.
On the other hand, Bakhtin  and Czerwik  introduced the concept of b-metric spaces (a generalization of metric spaces
) and proved the Banach contraction principle.
Chairman Department of Mathematics Government College University Lahore Dr Mujahid Abbas shared his views on 'Multivalued Mapping in Fuzzy Metric Spaces
are equivalent for all metric spaces
(X, [rho]), ([A.sub.k]) [subset] CL(X) and A [member of] CL(X).