This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Metamath Proof Explorer
Theorem 1xr
Description: 1 is an extended real number. (Contributed by Glauco Siliprandi, 2-Jan-2022)
|
|
Ref |
Expression |
|
Assertion |
1xr |
|- 1 e. RR* |
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
1re |
|- 1 e. RR |
| 2 |
1
|
rexri |
|- 1 e. RR* |