Theorem halfcld

Description: Closure of half of a number (frequently used special case). (Contributed by Mario Carneiro, 27-May-2016)

	Ref	Expression
Hypothesis	2timesd.1	$$⊢\phi \to A\in ℂ$$
Assertion	halfcld	$$⊢\phi \to \frac{A}{2}\in ℂ$$

Proof

Step	Hyp	Ref	Expression
1		2timesd.1	$$⊢\phi \to A\in ℂ$$
2		halfcl	$$⊢A\in ℂ\to \frac{A}{2}\in ℂ$$
3	1 2	syl	$$⊢\phi \to \frac{A}{2}\in ℂ$$