Theorem nfnae

Description: All variables are effectively bound in a distinct variable specifier. Usage of this theorem is discouraged because it depends on ax-13 . Use the weaker nfnaew when possible. (Contributed by Mario Carneiro, 11-Aug-2016) (New usage is discouraged.)

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

Proof

Step	Hyp	Ref	Expression
1		nfae	$$⊢Ⅎz\forall xx=y$$
2	1	nfn	$$⊢Ⅎz\neg \forall xx=y$$