Theorem nffal

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

	Ref	Expression
Assertion	nffal	⊢ Ⅎ 𝑥 ⊥

Proof

Step	Hyp	Ref	Expression
1		fal	⊢ ¬ ⊥
2	1	nfnth	⊢ Ⅎ 𝑥 ⊥