Theorem bj-evalf

Description: The evaluation at a class is a function from the universal class into the universal class. (Contributed by BJ, 17-Mar-2026)

	Ref	Expression
Assertion	bj-evalf	$$⊢\mathrm{Slot}A:\mathrm{V}⟶\mathrm{V}$$

Proof

Step	Hyp	Ref	Expression
1		df-slot	$$⊢\mathrm{Slot}A=\left(f\in \mathrm{V}⟼f\left(A\right)\right)$$
2		fvexd	$$⊢f\in \mathrm{V}\to f\left(A\right)\in \mathrm{V}$$
3	1 2	fmpti	$$⊢\mathrm{Slot}A:\mathrm{V}⟶\mathrm{V}$$