Description: The limit of a sequence of extended real numbers is an extended real number. (Contributed by Glauco Siliprandi, 5-Feb-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | xlimcl | ⊢ ( 𝐹 ~~>* 𝐴 → 𝐴 ∈ ℝ* ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | letopon | ⊢ ( ordTop ‘ ≤ ) ∈ ( TopOn ‘ ℝ* ) | |
2 | df-xlim | ⊢ ~~>* = ( ⇝𝑡 ‘ ( ordTop ‘ ≤ ) ) | |
3 | 2 | breqi | ⊢ ( 𝐹 ~~>* 𝐴 ↔ 𝐹 ( ⇝𝑡 ‘ ( ordTop ‘ ≤ ) ) 𝐴 ) |
4 | 3 | biimpi | ⊢ ( 𝐹 ~~>* 𝐴 → 𝐹 ( ⇝𝑡 ‘ ( ordTop ‘ ≤ ) ) 𝐴 ) |
5 | lmcl | ⊢ ( ( ( ordTop ‘ ≤ ) ∈ ( TopOn ‘ ℝ* ) ∧ 𝐹 ( ⇝𝑡 ‘ ( ordTop ‘ ≤ ) ) 𝐴 ) → 𝐴 ∈ ℝ* ) | |
6 | 1 4 5 | sylancr | ⊢ ( 𝐹 ~~>* 𝐴 → 𝐴 ∈ ℝ* ) |