# Section 1.3 - Methods and Techniques

Now that we've seen the definition of relations and some examples, we can think about some of their unique properties.

# Videos

Relations have three properties that are of special interest: the reflexive, symmetric and transitive properties. We're going to define them in this lecture and look at some quick examples then look at more detailed examples in the next lecture. (lecture slides)

In this lecture, we're going to look at some specific examples of how to show when a relation is symmetric, reflexive (lecture slides)

Closures are something you see in many fields. The "transitive closure" refers to the smallest transitive relation that "contains" a non-transitive one. (lecture slides)