Metamath Proof Explorer


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 Slot 𝐴 : V ⟶ V

Proof

Step Hyp Ref Expression
1 df-slot ⊢ Slot 𝐴 = ( 𝑓 ∈ V ↦ ( 𝑓 ‘ 𝐴 ) )
2 fvexd ⊢ ( 𝑓 ∈ V → ( 𝑓 ‘ 𝐴 ) ∈ V )
3 1 2 fmpti ⊢ Slot 𝐴 : V ⟶ V