Union with Universal Set
Theorem
The union of a set with the universal set is the universal set:
- $\mathbb U \cup S = \mathbb U$
Proof
| \(\ds S\) | \(\subseteq\) | \(\ds \mathbb U\) | Definition of Universal Set | |||||||||||
| \(\ds \leadstoandfrom \ \ \) | \(\ds \mathbb U \cup S\) | \(=\) | \(\ds \mathbb U\) | Union with Superset is Superset‎ |
$\blacksquare$
Also see
Sources
- 1967: George McCarty: Topology: An Introduction with Application to Topological Groups ... (previous) ... (next): Chapter $\text{I}$: Sets and Functions: Exercise $\text{B ii}$
- 2008: Paul Halmos and Steven Givant: Introduction to Boolean Algebras ... (previous) ... (next): $\S 2$
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): algebra of sets: $\text {(iv)}$
- 2021: Richard Earl and James Nicholson: The Concise Oxford Dictionary of Mathematics (6th ed.) ... (previous) ... (next): algebra of sets: $\text {(iv)}$