Theorem negidi

Description: Addition of a number and its negative. (Contributed by NM, 26-Nov-1994)

	Ref	Expression
Hypothesis	negidi.1	⊢ 𝐴 ∈ ℂ
Assertion	negidi	⊢ ( 𝐴 + - 𝐴 ) = 0

Proof

Step	Hyp	Ref	Expression
1		negidi.1	⊢ 𝐴 ∈ ℂ
2		negid	⊢ ( 𝐴 ∈ ℂ → ( 𝐴 + - 𝐴 ) = 0 )
3	1 2	ax-mp	⊢ ( 𝐴 + - 𝐴 ) = 0