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 ) |