Metamath Proof Explorer


Theorem elpwbi

Description: Membership in a power set, biconditional. (Contributed by Steven Nguyen, 17-Jul-2022) (Proof shortened by Steven Nguyen, 16-Sep-2022)

Ref Expression
Hypothesis elpwbi.1 B V
Assertion elpwbi A B A 𝒫 B

Proof

Step Hyp Ref Expression
1 elpwbi.1 B V
2 1 elpw2 A 𝒫 B A B
3 2 bicomi A B A 𝒫 B