Complement of Empty Set is Universe

Theorem
The complement of the empty set is the universe:


 * $\complement \left({\varnothing}\right) = \mathbb U$

Proof
Substitute $\mathbb U$ for $S$ in $\complement_S \left({\varnothing}\right) = S$ from Relative Complement of Empty Set.

Also see

 * Complement of Universe is Empty Set