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Metamath Proof Explorer

Theorem negidd

Description: Addition of a number and its negative. (Contributed by Mario Carneiro, 27-May-2016)

		Ref	Expression
	Hypothesis	negidd.1	$⊢ φ \to A \in ℂ$
	Assertion	negidd	$⊢ φ \to A + (- A) = 0$

Step	Hyp	Ref	Expression
1		negidd.1	$⊢ φ \to A \in ℂ$
2		negid	$⊢ A \in ℂ \to A + (- A) = 0$
3	1 2	syl	$⊢ φ \to A + (- A) = 0$