👉 Setness is a concept in mathematics and logic that refers to the property of a set of objects or elements being "present" or "existing." It is often used to describe the presence, existence, or membership of an object within a defined space. For example, if we have a set of numbers {1, 2, 3}, this setness means that all the numbers in the set are present and exist. In programming, setness can be seen as a property of objects or