The plan for today is to take some pain medicine, finish packing, and watch at least one good movie. I may try to go for a run, as the half marathon is less than a month away, but weâll see how Iâm feeling later. The moral of the story is: Iâm happy. Iâm ready.
Extensional definition. An extensional definition of a concept or term formulates its meaning by specifying its extension, that is, every object that falls under the definition of the concept or term in question.
The Empty Set and Set Equality. This lesson is part of a series of lessons on sets. In this lesson, we will learn how to define sets, the empty set, equal sets, subset, superset, proper subset, and proper superset. The Null set or Empty set. There are some sets that do not contain any element at all. For example, the set of months with 32 days. We call a set with no elements the null or empty set. It is represented by the symbol { } or Ã¸ . The set of dogs with six legs. The set of squares with 5 sides. The set of cars with 20 doors.