Theorem nfeq2

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

	Ref	Expression
Hypothesis	nfeq2.1	⊢ Ⅎ 𝑥 𝐵
Assertion	nfeq2	⊢ Ⅎ 𝑥 𝐴 = 𝐵

Proof

Step	Hyp	Ref	Expression
1		nfeq2.1	⊢ Ⅎ 𝑥 𝐵
2		nfcv	⊢ Ⅎ 𝑥 𝐴
3	2 1	nfeq	⊢ Ⅎ 𝑥 𝐴 = 𝐵