Description: The infimum of an arbitrary set of extended reals is an extended real. (Contributed by Glauco Siliprandi, 26-Jun-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | infxrcld.1 | ⊢ ( 𝜑 → 𝐴 ⊆ ℝ* ) | |
| Assertion | infxrcld | ⊢ ( 𝜑 → inf ( 𝐴 , ℝ* , < ) ∈ ℝ* ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | infxrcld.1 | ⊢ ( 𝜑 → 𝐴 ⊆ ℝ* ) | |
| 2 | infxrcl | ⊢ ( 𝐴 ⊆ ℝ* → inf ( 𝐴 , ℝ* , < ) ∈ ℝ* ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → inf ( 𝐴 , ℝ* , < ) ∈ ℝ* ) |