Theorem neghalfpire

Description: -u _pi / 2 is real. (Contributed by David A. Wheeler, 8-Dec-2018)

	Ref	Expression
Assertion	neghalfpire	|- -u ( _pi / 2 ) e. RR

Proof

Step	Hyp	Ref	Expression
1		halfpire	|- ( _pi / 2 ) e. RR
2	1	renegcli	|- -u ( _pi / 2 ) e. RR