Theorem nftht

Description: Closed form of nfth . (Contributed by Wolf Lammen, 19-Aug-2018) (Proof shortened by BJ, 16-Sep-2021) (Proof shortened by Wolf Lammen, 3-Sep-2022)

	Ref	Expression
Assertion	nftht	$$⊢\forall x\phi \to Ⅎx\phi$$

Proof

Step	Hyp	Ref	Expression
1		ax-1	$$⊢\forall x\phi \to \left(\exists x\phi \to \forall x\phi \right)$$
2	1	nfd	$$⊢\forall x\phi \to Ⅎx\phi$$