Metamath Proof Explorer


Theorem fsetex

Description: The set of functions between two classes exists if the codomain exists. Generalization of mapex to arbitrary domains. (Contributed by AV, 14-Aug-2024)

Ref Expression
Assertion fsetex BVf|f:ABV

Proof

Step Hyp Ref Expression
1 mapfset BVf|f:AB=BA
2 ovex BAV
3 1 2 eqeltrdi BVf|f:ABV