Theorem nfnaewOLD

Description: Obsolete version of nfnaew as of 25-Sep-2024. (Contributed by Mario Carneiro, 11-Aug-2016) (Revised by GG, 10-Jan-2024) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	nfnaewOLD	$$⊢Ⅎz\neg \forall xx=y$$

Proof

Step	Hyp	Ref	Expression
1		hbaev	$$⊢\forall xx=y\to \forall z\forall xx=y$$
2	1	nf5i	$$⊢Ⅎz\forall xx=y$$
3	2	nfn	$$⊢Ⅎz\neg \forall xx=y$$