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Metamath Proof Explorer

Theorem nfeq1

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

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

Proof

Step Hyp Ref Expression
1 nfeq1.1 ⊢ Ⅎ 𝑥 𝐴
2 nfcv ⊢ Ⅎ 𝑥 𝐵
3 1 2 nfeq ⊢ Ⅎ 𝑥 𝐴 = 𝐵