Partial Order Relation
## Definition / Concept
A relation is a partial order relation if it is reflexive, anti-symmetric and transitive.
## Formula
$$R\text{ is a partial order}\Leftrightarrow R\text{ is reflexive, anti-symmetric and transitive}$$
## Conditions / Special Cases
Reflexivity:
$$aRa\quad\forall a\in A$$
Anti-symmetry:
$$aRb,\ bRa\Rightarrow a=b$$
Transitivity:
$$aRb,\ bRc\Rightarrow aRc$$
## Terminologies
- Partially ordered set / Poset → A set together with a partial order relation.
## Usage
- Used in problems involving divisibility and subset relations.