Description: Closure of squaring in reals, deduction form. (Contributed by Mario Carneiro, 28-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | resqcld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ ) | |
| Assertion | resqcld | ⊢ ( 𝜑 → ( 𝐴 ↑ 2 ) ∈ ℝ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | resqcld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ ) | |
| 2 | resqcl | ⊢ ( 𝐴 ∈ ℝ → ( 𝐴 ↑ 2 ) ∈ ℝ ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → ( 𝐴 ↑ 2 ) ∈ ℝ ) |