##### On some new observations on Kurepa's left factorial

Nicola Fabiano; Nikola Mirkov; Zoran D. Mitrovic; Stojan Radenovic

Volume 4, Issue 3 , June 2022, , Pages 1-8
##### Abstract
After a brief historical excursus, we prove in a simple way some properties of Kurepa's function, the left factorial. We introduce Kurepa's hypothesis,  propose a new description, and the relation to Bezout's parameters and the Diophantine equation. A numerical analysis supports Kurepa's hypothesis ...  Read More

##### On Palais method in b-metric like spaces

Nikola Mirkov; Zoran D. Mitrovic; Mudasir Younis; Stjan Radenovic

Volume 3, Issue 3 , September 2021, , Pages 33-38
##### Abstract
This paper aims to prove that the Lipschitz constant in the Banach contraction principle belongs to the whole interval [0, 1) for all the six classes of spaces viz. metric spaces, b-metric spaces, partial metric spaces, partial b-metric spaces, metric like space, and finally for more general spaces called ...  Read More

##### The coincidence point results and rational contractions in E(s)-distance spaces

Maliha Rashid; Rabia Bibi; Reny George; Zoran D. Mitrovic

Volume 3, Issue 2 , June 2021, , Pages 55-67
##### Abstract
The purpose of this article is to clarify the concept of semi-interior points of positive cones by presenting some results and examples in this context.  Moreover, the new concept of E(s)-distance spaces is defined, which generalizes $E$-metric spaces. In addition, some coincidence point results ...  Read More