Theorem imnegi

Description: Imaginary part of negative. (Contributed by NM, 2-Aug-1999)

	Ref	Expression
Hypothesis	recl.1	$$⊢A\in ℂ$$
Assertion	imnegi	$$⊢\Im \left(-A\right)=-\Im \left(A\right)$$

Proof

Step	Hyp	Ref	Expression
1		recl.1	$$⊢A\in ℂ$$
2		imneg	$$⊢A\in ℂ\to \Im \left(-A\right)=-\Im \left(A\right)$$
3	1 2	ax-mp	$$⊢\Im \left(-A\right)=-\Im \left(A\right)$$