Description: Implicit substitution of a class for a setvar variable. (Contributed by ML, 17-Oct-2020)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | vtoclefex.1 | |- F/ x ph |
|
| vtoclefex.3 | |- ( x = A -> ph ) |
||
| Assertion | vtoclefex | |- ( A e. V -> ph ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | vtoclefex.1 | |- F/ x ph |
|
| 2 | vtoclefex.3 | |- ( x = A -> ph ) |
|
| 3 | 2 | ax-gen | |- A. x ( x = A -> ph ) |
| 4 | vtoclegft | |- ( ( A e. V /\ F/ x ph /\ A. x ( x = A -> ph ) ) -> ph ) |
|
| 5 | 1 3 4 | mp3an23 | |- ( A e. V -> ph ) |