Existence and Ulam–Hyers stability results of a coupled system of ψ -Hilfer sequential fractional differential equations

The major goal of this work is to investigate sufficient conditions of existence, uniqueness, and Ulam–Hyers stability of solutions for a coupled system of ψ-Hilfer sequential fractional differential equations with two-point boundary conditions. Some standard fixed point theorems of Leray–Schauder alternative and Banach are applied to establish these results. A pertinent example is provided to corroboration the results obtained.