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Metamath Proof Explorer

Theorem nffal

Description: The false constant has no free variables (see nftru ). (Contributed by BJ, 6-May-2019)

		Ref	Expression
	Assertion	nffal	$⊢ Ⅎ x ⊥$

Step	Hyp	Ref	Expression
1		fal	$⊢ \neg ⊥$
2	1	nfnth	$⊢ Ⅎ x ⊥$