# Logical OR

 Type classification: this is a lesson resource.

Welcome! This is a lesson in the Introductory Discrete Mathematics for Computer Science course here at Wikiversity.

Previous lesson: Logical AND

## The Disjunction

I apologize for the name of this lesson. The true name of this operator, which is a diadic operator, is a disjunction. It is sometimes called the inclusive OR operator, to distinguish it from another operator you'll learn about later. However, it is a bit dangerous to refer to a disjunction as an OR operator, because English words are far more vague than logic.

${\displaystyle \vee }$ : This is the disjunction, a.k.a. the (inclusive) OR operator

Let ${\displaystyle p}$ represent the statement: It is raining.
Let ${\displaystyle q}$ represent the statement: I am hungry.
${\displaystyle p\vee q}$ represents the disjunction of statements ${\displaystyle p}$ and ${\displaystyle q}$: It is raining OR I am hungry (OR it is raining AND I am hungry).

## Truth Table for the Disjunction

This is its truth table:

${\displaystyle p\,\!}$ ${\displaystyle q\,\!}$ ${\displaystyle p\vee q}$
T T T
T F T
F T T
F F F

## Next Lesson

The name of the next lesson is Logical XOR.