Definition: In mathematics, a correspondence is a relationship or mapping between two sets of objects. It is a concept that allows us to transform one set into another without changing its contents. In other words, it involves matching elements from one set with elements from another set in such a way that the original elements are preserved in both sets. For example, consider two sets: A = {1, 2} and B = {a, b}. We can create a correspondence between these sets by mapping each element