Metamath Proof Explorer


Theorem vtocle

Description: Implicit substitution of a class for a setvar variable. (Contributed by NM, 9-Sep-1993)

Ref Expression
Hypotheses vtocle.1 𝐴 ∈ V
vtocle.2 ( 𝑥 = 𝐴𝜑 )
Assertion vtocle 𝜑

Proof

Step Hyp Ref Expression
1 vtocle.1 𝐴 ∈ V
2 vtocle.2 ( 𝑥 = 𝐴𝜑 )
3 2 vtocleg ( 𝐴 ∈ V → 𝜑 )
4 1 3 ax-mp 𝜑