Theorem vtocle

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

	Ref	Expression
Hypotheses	vtocle.1	$$⊢A\in \mathrm{V}$$
	vtocle.2	$$⊢x=A\to \phi$$
Assertion	vtocle	$$⊢\phi$$

Proof

Step	Hyp	Ref	Expression
1		vtocle.1	$$⊢A\in \mathrm{V}$$
2		vtocle.2	$$⊢x=A\to \phi$$
3	2	vtocleg	$$⊢A\in \mathrm{V}\to \phi$$
4	1 3	ax-mp	$$⊢\phi$$