Description: Lemma for iscnrm3 . Subspace topology is a topology. (Contributed by Zhi Wang, 3-Sep-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | iscnrm3lem1 | |- ( J e. Top -> ( A. x e. A ph <-> A. x e. A ( ( J |`t x ) e. Top /\ ph ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | resttop | |- ( ( J e. Top /\ x e. A ) -> ( J |`t x ) e. Top ) |
|
2 | 1 | biantrurd | |- ( ( J e. Top /\ x e. A ) -> ( ph <-> ( ( J |`t x ) e. Top /\ ph ) ) ) |
3 | 2 | ralbidva | |- ( J e. Top -> ( A. x e. A ph <-> A. x e. A ( ( J |`t x ) e. Top /\ ph ) ) ) |