Theorem sqge0d

Description: The square of a real is nonnegative, deduction form. (Contributed by Mario Carneiro, 28-May-2016)

	Ref	Expression
Hypothesis	sqge0d.1	$$⊢\phi \to A\in ℝ$$
Assertion	sqge0d	$$⊢\phi \to 0\le A^2$$

Proof

Step	Hyp	Ref	Expression
1		sqge0d.1	$$⊢\phi \to A\in ℝ$$
2		sqge0	$$⊢A\in ℝ\to 0\le A^2$$
3	1 2	syl	$$⊢\phi \to 0\le A^2$$