Description: A class abstraction with a conjunction is a subset of the class abstraction with the right conjunct only. (Contributed by AV, 7-Aug-2024) (Proof shortened by SN, 22-Aug-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | abanssr | |- { f | ( ph /\ ps ) } C_ { f | ps } |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | simpr | |- ( ( ph /\ ps ) -> ps ) |
|
| 2 | 1 | ss2abi | |- { f | ( ph /\ ps ) } C_ { f | ps } |