Positivity and uniqueness of solutions for Riemann-Liouville fractional problem of delta types

In this paper, we explore multi positive solutions together with their existence and uniqueness, which is properly defined for delta fractional version of Riemann-Liouville difference operators. Our exploration encompasses two distinct directions. In the first direction, we construct the Green's function formula for the proposed delta fractional boundary value problems of order S is an element of (1, 2), and we present some essential properties of this function. The last and main results suggest using the well-known fixed point theorems in a Banach space for testing the existing and uniqueness of multi-positive solutions of such problems.