Description: Third component of a 3-dimensional real coordinate vector is real. (Contributed by Jiamin Zhao, 31-Jul-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | rr3fv.1 | ⊢ 𝐴 ∈ ( ℝ ↑m ( 1 ... 3 ) ) | |
| Assertion | rr3fv3cli | ⊢ ( 𝐴 ‘ 3 ) ∈ ℝ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rr3fv.1 | ⊢ 𝐴 ∈ ( ℝ ↑m ( 1 ... 3 ) ) | |
| 2 | rr3fvcl | ⊢ ( 𝐴 ∈ ( ℝ ↑m ( 1 ... 3 ) ) → ( ( 𝐴 ‘ 1 ) ∈ ℝ ∧ ( 𝐴 ‘ 2 ) ∈ ℝ ∧ ( 𝐴 ‘ 3 ) ∈ ℝ ) ) | |
| 3 | 1 2 | ax-mp | ⊢ ( ( 𝐴 ‘ 1 ) ∈ ℝ ∧ ( 𝐴 ‘ 2 ) ∈ ℝ ∧ ( 𝐴 ‘ 3 ) ∈ ℝ ) |
| 4 | 3 | simp3i | ⊢ ( 𝐴 ‘ 3 ) ∈ ℝ |