Theorem neghalfpirx

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

	Ref	Expression
Assertion	neghalfpirx	⊢ - ( π / 2 ) ∈ ℝ*

Proof

Step	Hyp	Ref	Expression
1		neghalfpire	⊢ - ( π / 2 ) ∈ ℝ
2	1	rexri	⊢ - ( π / 2 ) ∈ ℝ*