Description: From a restricted universal statement over A , specialize to an arbitrary element class, cf. rsp3 . (Contributed by Peter Mazsa, 9-Feb-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | rsp3.1 | |- F/_ x A |
|
| rsp3.2 | |- F/_ y A |
||
| rsp3.3 | |- F/ y ph |
||
| rsp3.4 | |- F/ x ps |
||
| rsp3.5 | |- ( x = y -> ( ph <-> ps ) ) |
||
| Assertion | rsp3eq | |- ( A. x e. A ph -> ( ( y = B /\ B e. A ) -> ps ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rsp3.1 | |- F/_ x A |
|
| 2 | rsp3.2 | |- F/_ y A |
|
| 3 | rsp3.3 | |- F/ y ph |
|
| 4 | rsp3.4 | |- F/ x ps |
|
| 5 | rsp3.5 | |- ( x = y -> ( ph <-> ps ) ) |
|
| 6 | eqeltr | |- ( ( y = B /\ B e. A ) -> y e. A ) |
|
| 7 | 1 2 3 4 5 | rsp3 | |- ( A. x e. A ph -> ( y e. A -> ps ) ) |
| 8 | 6 7 | syl5 | |- ( A. x e. A ph -> ( ( y = B /\ B e. A ) -> ps ) ) |