theorem Arroweq2d (_G: wff) (A _B1 _B2: set): $ _G -> _B1 == _B2 $ > $ _G -> Arrow A _B1 == Arrow A _B2 $;
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqsidd | _G -> A == A |
|
2 | hyp _h | _G -> _B1 == _B2 |
|
3 | 1, 2 | Arroweqd | _G -> Arrow A _B1 == Arrow A _B2 |