Fixed Point Results in Generalized Rectangular Metric Spaces in the Sense of Branciari and Their Applications

In this work, we will introduce a new type of space called the generalized rectangular ‐pseudo metric space, which generalizes the concept of metric space, rectangular metric space, ‐rectangular metric space, and pseudo metric space. Next, we will prove a generalization of the famous alternative fixed point theorem of Diaz and Margolis in such space. As applications of our result, we will study the Ulam‐stability of a delay differential equation with multiple variable time delays, and we will prove also the existence and uniqueness of the solution to a Fredholm integral equation.