Theorem xnegnegd

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

	Ref	Expression
Hypothesis	xnegnegd.1	⊢ ( 𝜑 → 𝐴 ∈ ℝ* )
Assertion	xnegnegd	⊢ ( 𝜑 → -𝑒 -𝑒 𝐴 = 𝐴 )

Proof

Step	Hyp	Ref	Expression
1		xnegnegd.1	⊢ ( 𝜑 → 𝐴 ∈ ℝ* )
2		xnegneg	⊢ ( 𝐴 ∈ ℝ* → -𝑒 -𝑒 𝐴 = 𝐴 )
3	1 2	syl	⊢ ( 𝜑 → -𝑒 -𝑒 𝐴 = 𝐴 )