Description: Nonnegative real numbers are real numbers. (Contributed by Thierry Arnoux, 9-Sep-2018) (Proof shortened by AV, 8-Sep-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rge0ssre | |- ( 0 [,) +oo ) C_ RR |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elrege0 | |- ( x e. ( 0 [,) +oo ) <-> ( x e. RR /\ 0 <_ x ) ) |
|
| 2 | 1 | simplbi | |- ( x e. ( 0 [,) +oo ) -> x e. RR ) |
| 3 | 2 | ssriv | |- ( 0 [,) +oo ) C_ RR |