Theorem renegcld

Description: Closure law for negative of reals. (Contributed by Mario Carneiro, 27-May-2016)

	Ref	Expression
Hypothesis	renegcld.1	|- ( ph -> A e. RR )
Assertion	renegcld	|- ( ph -> -u A e. RR )

Proof

Step	Hyp	Ref	Expression
1		renegcld.1	|- ( ph -> A e. RR )
2		renegcl	|- ( A e. RR -> -u A e. RR )
3	1 2	syl	|- ( ph -> -u A e. RR )