Theorem resqcld

Description: Closure of square in reals. (Contributed by Mario Carneiro, 28-May-2016)

	Ref	Expression
Hypothesis	resqcld.1	$$⊢\phi \to A\in ℝ$$
Assertion	resqcld	$$⊢\phi \to A^2\in ℝ$$

Proof

Step	Hyp	Ref	Expression
1		resqcld.1	$$⊢\phi \to A\in ℝ$$
2		resqcl	$$⊢A\in ℝ\to A^2\in ℝ$$
3	1 2	syl	$$⊢\phi \to A^2\in ℝ$$