In this paper we extend and generalize common fixed point theorems for six self-maps of Singh and Jain [B. Singh, S. Jain, A fixed point theorem in Menger space through weak compatibility, J. Math. An., Abstract In this paper, the concept of set-valued contraction of Nadler type in the setting of tvs-cone spaces was introduced and a fixed point theorem in the setting of tvs-cone spaces with respect., AbstractWe prove the existence of a fuzzy common fixed point of two mappings satisfying a generalized contractive condition. Our results provide extensions as well as substantial improvements of sever., In this paper, we prove that there are no null Mannheim curves in Minkowski 3-space. We also prove that the only pseudo null Mannheim curves in Minkowski 3-space are pseudo null straight lines and pse., We prove that some classes of summable sequences of positive real numbers satisfy several selection principles related to a special kind of convergence.