Description: Real closure of half. (Contributed by NM, 1-Jan-2006)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | rehalfcl | ⊢ ( 𝐴 ∈ ℝ → ( 𝐴 / 2 ) ∈ ℝ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 2re | ⊢ 2 ∈ ℝ | |
| 2 | 2ne0 | ⊢ 2 ≠ 0 | |
| 3 | redivcl | ⊢ ( ( 𝐴 ∈ ℝ ∧ 2 ∈ ℝ ∧ 2 ≠ 0 ) → ( 𝐴 / 2 ) ∈ ℝ ) | |
| 4 | 1 2 3 | mp3an23 | ⊢ ( 𝐴 ∈ ℝ → ( 𝐴 / 2 ) ∈ ℝ ) |