Theorem nfnfc1

Description: The setvar x is bound in F/_ x A . (Contributed by Mario Carneiro, 11-Aug-2016)

	Ref	Expression
Assertion	nfnfc1	$$⊢Ⅎx\underset{\_}{Ⅎ}xA$$

Proof

Step	Hyp	Ref	Expression
1		df-nfc	$$⊢\underset{\_}{Ⅎ}xA\leftrightarrow \forall yℲxy\in A$$
2		nfnf1	$$⊢ℲxℲxy\in A$$
3	2	nfal	$$⊢Ⅎx\forall yℲxy\in A$$
4	1 3	nfxfr	$$⊢Ⅎx\underset{\_}{Ⅎ}xA$$