Metamath Proof Explorer


Theorem csbied

Description: Conversion of implicit substitution to explicit substitution into a class. (Contributed by Mario Carneiro, 2-Dec-2014) (Revised by Mario Carneiro, 13-Oct-2016)

Ref Expression
Hypotheses csbied.1 ( 𝜑𝐴𝑉 )
csbied.2 ( ( 𝜑𝑥 = 𝐴 ) → 𝐵 = 𝐶 )
Assertion csbied ( 𝜑 𝐴 / 𝑥 𝐵 = 𝐶 )

Proof

Step Hyp Ref Expression
1 csbied.1 ( 𝜑𝐴𝑉 )
2 csbied.2 ( ( 𝜑𝑥 = 𝐴 ) → 𝐵 = 𝐶 )
3 nfv 𝑥 𝜑
4 nfcvd ( 𝜑 𝑥 𝐶 )
5 3 4 1 2 csbiedf ( 𝜑 𝐴 / 𝑥 𝐵 = 𝐶 )