Description: Any set is a subset of itself. (Contributed by Peter Mazsa, 1-Aug-2019)
Ref | Expression | ||
---|---|---|---|
Assertion | brssrid | |- ( A e. V -> A _S A ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssid | |- A C_ A |
|
2 | brssr | |- ( A e. V -> ( A _S A <-> A C_ A ) ) |
|
3 | 1 2 | mpbiri | |- ( A e. V -> A _S A ) |