Theorem nffal

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

	Ref	Expression
Assertion	nffal	$$⊢Ⅎx\perp$$

Proof

Step	Hyp	Ref	Expression
1		fal	$$⊢\neg \perp$$
2	1	nfnth	$$⊢Ⅎx\perp$$