Theorem xnegnegi

Description: Extended real version of negneg . (Contributed by Glauco Siliprandi, 2-Jan-2022)

	Ref	Expression
Hypothesis	xnegnegi.1	⊢ 𝐴 ∈ ℝ*
Assertion	xnegnegi	⊢ -𝑒 -𝑒 𝐴 = 𝐴

Proof

Step	Hyp	Ref	Expression
1		xnegnegi.1	⊢ 𝐴 ∈ ℝ*
2		xnegneg	⊢ ( 𝐴 ∈ ℝ* → -𝑒 -𝑒 𝐴 = 𝐴 )
3	1 2	ax-mp	⊢ -𝑒 -𝑒 𝐴 = 𝐴