theorem Powereqd (_G: wff) (_A1 _A2: set): $ _G -> _A1 == _A2 $ > $ _G -> Power _A1 == Power _A2 $;
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqsidd | _G -> x == x |
|
2 | hyp _Ah | _G -> _A1 == _A2 |
|
3 | 1, 2 | sseqd | _G -> (x C_ _A1 <-> x C_ _A2) |
4 | 3 | abeqd | _G -> {x | x C_ _A1} == {x | x C_ _A2} |
5 | 4 | conv Power | _G -> Power _A1 == Power _A2 |