Relations and Functions: What is a Partial Order Relation? (POSET) Part 2

In this video, we define what it means for a relation to be a partial order (POSET). In particular, we define a partial order relation to be one that is reflexive, anti-symmetric, and transitive. We construct a partial ordering by considering a relation and closing it under the three requirements, hence ending with a partial order relation.

[Papaabe]

Please I need a video on the preimage of a function with solved examples

[Papaabe]

Using a graph to find the preimage of the set of a function

[JP-xmqf]

on min 4:09, for R3, would it still be reflexive even if we take out (8, 8)? as it would still be a subset of A, just without all the reflexive pairs.