Description: Closure of extended real negative. (Contributed by Glauco Siliprandi, 2-Jan-2022)
Ref | Expression | ||
---|---|---|---|
Hypothesis | xnegcli.1 | ⊢ 𝐴 ∈ ℝ* | |
Assertion | xnegcli | ⊢ -𝑒 𝐴 ∈ ℝ* |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | xnegcli.1 | ⊢ 𝐴 ∈ ℝ* | |
2 | xnegcl | ⊢ ( 𝐴 ∈ ℝ* → -𝑒 𝐴 ∈ ℝ* ) | |
3 | 1 2 | ax-mp | ⊢ -𝑒 𝐴 ∈ ℝ* |