Description: The supremum of an arbitrary set of extended reals is an extended real. (Contributed by Glauco Siliprandi, 2-Jan-2022)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | supxrcli.1 | ⊢ 𝐴 ⊆ ℝ* | |
| Assertion | supxrcli | ⊢ sup ( 𝐴 , ℝ* , < ) ∈ ℝ* |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | supxrcli.1 | ⊢ 𝐴 ⊆ ℝ* | |
| 2 | supxrcl | ⊢ ( 𝐴 ⊆ ℝ* → sup ( 𝐴 , ℝ* , < ) ∈ ℝ* ) | |
| 3 | 1 2 | ax-mp | ⊢ sup ( 𝐴 , ℝ* , < ) ∈ ℝ* |