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 | ||
Assertion | elpwbi |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elpwbi.1 | ||
2 | 1 | elpw2 | |
3 | 2 | bicomi |