Theorem nfel1

Description: Hypothesis builder for elementhood, special case. (Contributed by Mario Carneiro, 10-Oct-2016)

	Ref	Expression
Hypothesis	nfeq1.1	$$⊢\underset{\_}{Ⅎ}xA$$
Assertion	nfel1	$$⊢ℲxA\in B$$

Proof

Step	Hyp	Ref	Expression
1		nfeq1.1	$$⊢\underset{\_}{Ⅎ}xA$$
2		nfcv	$$⊢\underset{\_}{Ⅎ}xB$$
3	1 2	nfel	$$⊢ℲxA\in B$$