---
id: 2025-12-02T10:57:00-0500
title: 2025-12-02 10:57:??
tags:
daily: "[[2025-12-02]]"
---
# 2025-12-02 10:57:??

### Set Notation Example

Let $A$ and $B$ be sets
sharing some but not all elements.

* $A \cap B \neq \varnothing$:
    "The intersection of $A$ and $B$ is nonempty"
    (They share at least one element).

* $A \not\subseteq B$:
    "$A$ is not a subset of $B$"
    ($A$ has at least one element not in $B$).
    Equivalent to $A \setminus B \neq \varnothing$.

* $B \not\subseteq A$:
    "$B$ is not a subset of $A$"
    ($B$ has at least one element not in $A$).
    Equivalent to $B \setminus A \neq \varnothing$.
