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Metamath Proof Explorer

Theorem elndif

Description: A set does not belong to a class excluding it. (Contributed by NM, 27-Jun-1994)

		Ref	Expression
	Assertion	elndif	$⊢ A \in B \to \neg A \in (C ∖ B)$

Step	Hyp	Ref	Expression
1		eldifn	$⊢ A \in (C ∖ B) \to \neg A \in B$
2	1	con2i	$⊢ A \in B \to \neg A \in (C ∖ B)$