Description: Deduction version of sbcth . (Contributed by NM, 30-Nov-2005) (Proof shortened by Andrew Salmon, 8-Jun-2011)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | sbcthdv.1 | |- ( ph -> ps ) |
|
| Assertion | sbcthdv | |- ( ( ph /\ A e. V ) -> [. A / x ]. ps ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sbcthdv.1 | |- ( ph -> ps ) |
|
| 2 | 1 | alrimiv | |- ( ph -> A. x ps ) |
| 3 | spsbc | |- ( A e. V -> ( A. x ps -> [. A / x ]. ps ) ) |
|
| 4 | 2 3 | mpan9 | |- ( ( ph /\ A e. V ) -> [. A / x ]. ps ) |