Let $X$ be a set. The axiom of power set and the axiom of empty ensure 
* the existence of the power set, \(\mathcal P(X) :=\{A\mid  A\subseteq X\}\), i.e. the set of all possible subsets of \(X\)1, and
* that the empty set \(\emptyset\) is a subset any non-empty set \(X\).
Applications: 1 
Axioms: 2 
Corollaries: 3 
Definitions: 4 5 6 
Examples: 7 8 
Explanations: 9 
Parts: 10 
Proofs: 11 12 13 14 
Propositions: 15 16 
Please note that the power set of the empty set is \(\mathcal P(\emptyset)=\{\emptyset,\{\emptyset\}\}\). ↩