theorem receq3d (_G: wff) (z: nat) (S: set) (_n1 _n2: nat): $ _G -> _n1 = _n2 $ > $ _G -> rec z S _n1 = rec z S _n2 $;
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqidd | _G -> z = z  | 
        |
| 2 | eqsidd | _G -> S == S  | 
        |
| 3 | hyp _h | _G -> _n1 = _n2  | 
        |
| 4 | 1, 2, 3 | receqd | _G -> rec z S _n1 = rec z S _n2  |