Description: Restricted quantifier version of spesbcd . (Contributed by Eric Schmidt, 29-Sep-2025)
Ref | Expression | ||
---|---|---|---|
Hypotheses | rspesbcd.1 | |- ( ph -> A e. B ) |
|
rspesbcd.2 | |- ( ph -> [. A / x ]. ps ) |
||
Assertion | rspesbcd | |- ( ph -> E. x e. B ps ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rspesbcd.1 | |- ( ph -> A e. B ) |
|
2 | rspesbcd.2 | |- ( ph -> [. A / x ]. ps ) |
|
3 | sbcel1v | |- ( [. A / x ]. x e. B <-> A e. B ) |
|
4 | 1 3 | sylibr | |- ( ph -> [. A / x ]. x e. B ) |
5 | sbcan | |- ( [. A / x ]. ( x e. B /\ ps ) <-> ( [. A / x ]. x e. B /\ [. A / x ]. ps ) ) |
|
6 | 4 2 5 | sylanbrc | |- ( ph -> [. A / x ]. ( x e. B /\ ps ) ) |
7 | 6 | spesbcd | |- ( ph -> E. x ( x e. B /\ ps ) ) |
8 | df-rex | |- ( E. x e. B ps <-> E. x ( x e. B /\ ps ) ) |
|
9 | 7 8 | sylibr | |- ( ph -> E. x e. B ps ) |