theorem Powereqd (_G: wff) (_A1 _A2: set): $ _G -> _A1 == _A2 $ > $ _G -> Power _A1 == Power _A2 $;
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | hyp _Ah | _G -> _A1 == _A2 |
|
| 2 | 1 | sseq2d | _G -> (x C_ _A1 <-> x C_ _A2) |
| 3 | 2 | abeqd | _G -> {x | x C_ _A1} == {x | x C_ _A2} |
| 4 | 3 | conv Power | _G -> Power _A1 == Power _A2 |