Because the arthroscope and surgical instruments are thin, your surgeon can use very small incisions, rather than the larger incision needed for open surgery. This results in less pain for patients, less joint stiffness, and often shortens the time it takes to recover and return to favorite activities. During arthroscopy, your surgeon can see the structures of your knee in great detail on a video monitor.
For a function of three variables, a level set is a surface in three-dimensional space that we will call a level surface. For a constant value $c$ in the range of $f(x,y,z)$, the level surface of $f$ is the implicit surface given by the graph of $c=f(x,y,z)$.
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.