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Metamath Proof Explorer

Theorem rexnegd

Description: Minus a real number. (Contributed by Glauco Siliprandi, 2-Jan-2022)

		Ref	Expression
	Hypothesis	rexnegd.1	$⊢ φ \to A \in ℝ$
	Assertion	rexnegd	$⊢ φ \to - A = - A$

Step	Hyp	Ref	Expression
1		rexnegd.1	$⊢ φ \to A \in ℝ$
2		rexneg	$⊢ A \in ℝ \to - A = - A$
3	1 2	syl	$⊢ φ \to - A = - A$