Description: Equality theorem for shift-stability of two classes. (Contributed by Peter Mazsa, 19-Feb-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | shiftstableeq2 | |- ( F = G -> ( S ShiftStable F ) = ( S ShiftStable G ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | coeq2 | |- ( F = G -> ( S o. F ) = ( S o. G ) ) |
|
| 2 | id | |- ( F = G -> F = G ) |
|
| 3 | 1 2 | ineq12d | |- ( F = G -> ( ( S o. F ) i^i F ) = ( ( S o. G ) i^i G ) ) |
| 4 | df-shiftstable | |- ( S ShiftStable F ) = ( ( S o. F ) i^i F ) |
|
| 5 | df-shiftstable | |- ( S ShiftStable G ) = ( ( S o. G ) i^i G ) |
|
| 6 | 3 4 5 | 3eqtr4g | |- ( F = G -> ( S ShiftStable F ) = ( S ShiftStable G ) ) |