Theorem nfel1

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

	Ref	Expression
Hypothesis	nfeq1.1	⊢ Ⅎ 𝑥 𝐴
Assertion	nfel1	⊢ Ⅎ 𝑥 𝐴 ∈ 𝐵

Proof

Step	Hyp	Ref	Expression
1		nfeq1.1	⊢ Ⅎ 𝑥 𝐴
2		nfcv	⊢ Ⅎ 𝑥 𝐵
3	1 2	nfel	⊢ Ⅎ 𝑥 𝐴 ∈ 𝐵