Metamath Proof Explorer


Theorem nfeq1

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

Ref Expression
Hypothesis nfeq1.1
|- F/_ x A
Assertion nfeq1
|- F/ x A = B

Proof

Step Hyp Ref Expression
1 nfeq1.1
 |-  F/_ x A
2 nfcv
 |-  F/_ x B
3 1 2 nfeq
 |-  F/ x A = B