Description: Restricted specialization. (Contributed by NM, 17-Oct-1996)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rsp | |- ( A. x e. A ph -> ( x e. A -> ph ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-ral | |- ( A. x e. A ph <-> A. x ( x e. A -> ph ) ) |
|
| 2 | sp | |- ( A. x ( x e. A -> ph ) -> ( x e. A -> ph ) ) |
|
| 3 | 1 2 | sylbi | |- ( A. x e. A ph -> ( x e. A -> ph ) ) |