Description: Closure of exponentiation of rationals. For integer exponents, see qexpclz . (Contributed by NM, 16-Dec-2005)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | qexpcl | ⊢ ( ( 𝐴 ∈ ℚ ∧ 𝑁 ∈ ℕ0 ) → ( 𝐴 ↑ 𝑁 ) ∈ ℚ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | qsscn | ⊢ ℚ ⊆ ℂ | |
| 2 | qmulcl | ⊢ ( ( 𝑥 ∈ ℚ ∧ 𝑦 ∈ ℚ ) → ( 𝑥 · 𝑦 ) ∈ ℚ ) | |
| 3 | 1q | ⊢ 1 ∈ ℚ | |
| 4 | 1 2 3 | expcllem | ⊢ ( ( 𝐴 ∈ ℚ ∧ 𝑁 ∈ ℕ0 ) → ( 𝐴 ↑ 𝑁 ) ∈ ℚ ) |