theorem writeeq2d (_G: wff) (F: set) (_a1 _a2 b: nat): $ _G -> _a1 = _a2 $ > $ _G -> write F _a1 b == write F _a2 b $;
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqsidd | _G -> F == F |
|
2 | hyp _h | _G -> _a1 = _a2 |
|
3 | eqidd | _G -> b = b |
|
4 | 1, 2, 3 | writeeqd | _G -> write F _a1 b == write F _a2 b |