👉 In geometry and algebra, a Castrenian is a subset of a given set. A set X is a Castrenian if it contains all its proper subsets. This means that every element in X can be expressed as a unique combination of elements from the set X. For instance, consider the set {1, 2, 3}. The union of this set with itself (which is also considered to be a subset) will always result in an empty set, since there are no elements
