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Metamath Proof Explorer

Theorem subidi

Description: Subtraction of a number from itself. (Contributed by NM, 26-Nov-1994)

		Ref	Expression
	Hypothesis	negidi.1	$⊢ A \in ℂ$
	Assertion	subidi	$⊢ A - A = 0$

Step	Hyp	Ref	Expression
1		negidi.1	$⊢ A \in ℂ$
2		subid	$⊢ A \in ℂ \to A - A = 0$
3	1 2	ax-mp	$⊢ A - A = 0$