theorem zeqmeq1d (_G: wff) (_n1 _n2 a b: nat): $ _G -> _n1 = _n2 $ > $ _G -> (modZ(_n1): a = b <-> modZ(_n2): a = b) $;
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | hyp _h | _G -> _n1 = _n2 |
|
| 2 | eqidd | _G -> a = a |
|
| 3 | eqidd | _G -> b = b |
|
| 4 | 1, 2, 3 | zeqmeqd | _G -> (modZ(_n1): a = b <-> modZ(_n2): a = b) |