Description: A substitution into a theorem. (Contributed by NM, 1-Mar-2008) (Proof shortened by Mario Carneiro, 13-Oct-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | sbcth2.1 | |- ( x e. B -> ph ) |
|
| Assertion | sbcth2 | |- ( A e. B -> [. A / x ]. ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sbcth2.1 | |- ( x e. B -> ph ) |
|
| 2 | 1 | rgen | |- A. x e. B ph |
| 3 | rspsbc | |- ( A e. B -> ( A. x e. B ph -> [. A / x ]. ph ) ) |
|
| 4 | 2 3 | mpi | |- ( A e. B -> [. A / x ]. ph ) |