Metamath Proof Explorer


Theorem supxrcld

Description: The supremum of an arbitrary set of extended reals is an extended real. (Contributed by Glauco Siliprandi, 26-Jun-2021)

Ref Expression
Hypothesis supxrcld.1 ⊢ φ → A ⊆ ℝ *
Assertion supxrcld ⊢ φ → sup A ℝ * < ∈ ℝ *

Proof

Step Hyp Ref Expression
1 supxrcld.1 ⊢ φ → A ⊆ ℝ *
2 supxrcl ⊢ A ⊆ ℝ * → sup A ℝ * < ∈ ℝ *
3 1 2 syl ⊢ φ → sup A ℝ * < ∈ ℝ *