Description: A n-dimensional open interval is a subset of the half-open interval with the same bounds. (Contributed by Glauco Siliprandi, 8-Apr-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ioosshoi | |- X_ k e. X ( A (,) B ) C_ X_ k e. X ( A [,) B ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nftru | |- F/ k T. |
|
| 2 | ioossico | |- ( A (,) B ) C_ ( A [,) B ) |
|
| 3 | 2 | a1i | |- ( ( T. /\ k e. X ) -> ( A (,) B ) C_ ( A [,) B ) ) |
| 4 | 1 3 | ixpssixp | |- ( T. -> X_ k e. X ( A (,) B ) C_ X_ k e. X ( A [,) B ) ) |
| 5 | 4 | mptru | |- X_ k e. X ( A (,) B ) C_ X_ k e. X ( A [,) B ) |