Theorem msqge0d

Description: A square is nonnegative. (Contributed by Mario Carneiro, 27-May-2016)

	Ref	Expression
Hypothesis	leidd.1	⊢ ( 𝜑 → 𝐴 ∈ ℝ )
Assertion	msqge0d	⊢ ( 𝜑 → 0 ≤ ( 𝐴 · 𝐴 ) )

Proof

Step	Hyp	Ref	Expression
1		leidd.1	⊢ ( 𝜑 → 𝐴 ∈ ℝ )
2		msqge0	⊢ ( 𝐴 ∈ ℝ → 0 ≤ ( 𝐴 · 𝐴 ) )
3	1 2	syl	⊢ ( 𝜑 → 0 ≤ ( 𝐴 · 𝐴 ) )