Description: The empty intersection in a topology is realized by the base set. (Contributed by Zhi Wang, 30-Sep-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | topclat.i | |- I = ( toInc ` J ) |
|
toplatlub.j | |- ( ph -> J e. Top ) |
||
toplatglb0.g | |- G = ( glb ` I ) |
||
Assertion | toplatglb0 | |- ( ph -> ( G ` (/) ) = U. J ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | topclat.i | |- I = ( toInc ` J ) |
|
2 | toplatlub.j | |- ( ph -> J e. Top ) |
|
3 | toplatglb0.g | |- G = ( glb ` I ) |
|
4 | 3 | a1i | |- ( ph -> G = ( glb ` I ) ) |
5 | eqid | |- U. J = U. J |
|
6 | 5 | topopn | |- ( J e. Top -> U. J e. J ) |
7 | 2 6 | syl | |- ( ph -> U. J e. J ) |
8 | 1 4 7 | ipoglb0 | |- ( ph -> ( G ` (/) ) = U. J ) |