Description: The equivalence between neighborhood and open neighborhood. See opnneieqvv for different dummy variables. (Contributed by Zhi Wang, 31-Aug-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | opnneir.1 | |
|
opnneilv.2 | |
||
opnneil.3 | |
||
Assertion | opnneieqv | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | opnneir.1 | |
|
2 | opnneilv.2 | |
|
3 | opnneil.3 | |
|
4 | 1 2 3 | opnneil | |
5 | 1 | opnneir | |
6 | 4 5 | impbid | |