👉 In mathematics, a subbase of a set S is defined as a subset that contains all elements of S that are less than or equal to each element in S. This means that if we have a set S and its subbase B, then every element of B is also an element of S. For example, consider the set {1, 2, 3} with its subbase B = {1, 2}. In this case, all elements of B are less than or