Description: An open interval is a set of complex numbers. (Contributed by Glauco Siliprandi, 11-Dec-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ioosscn | |- ( A (,) B ) C_ CC |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ioossre | |- ( A (,) B ) C_ RR |
|
| 2 | ax-resscn | |- RR C_ CC |
|
| 3 | 1 2 | sstri | |- ( A (,) B ) C_ CC |