theorem lreceq2d (_G: wff) (z: nat) (_S1 _S2: set) (n: nat): $ _G -> _S1 == _S2 $ > $ _G -> lrec z _S1 n = lrec z _S2 n $;
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqidd | _G -> z = z | |
| 2 | hyp _h | _G -> _S1 == _S2 | |
| 3 | eqidd | _G -> n = n | |
| 4 | 1, 2, 3 | lreceqd | _G -> lrec z _S1 n = lrec z _S2 n |