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Metamath Proof Explorer

Theorem absnegd

Description: Absolute value of negative. (Contributed by Mario Carneiro, 29-May-2016)

		Ref	Expression
	Hypothesis	abscld.1	$⊢ φ \to A \in ℂ$
	Assertion	absnegd	$⊢ φ \to \|- A\| = \|A\|$

Step	Hyp	Ref	Expression
1		abscld.1	$⊢ φ \to A \in ℂ$
2		absneg	$⊢ A \in ℂ \to \|- A\| = \|A\|$
3	1 2	syl	$⊢ φ \to \|- A\| = \|A\|$