Metamath Proof Explorer


Theorem fsetsspwxp

Description: The class of all functions from A into B is a subclass of the power class of the cartesion product of A and B . (Contributed by AV, 13-Sep-2024)

Ref Expression
Assertion fsetsspwxp ⊢ f | f : A ⟶ B ⊆ 𝒫 A × B

Proof

Step Hyp Ref Expression
1 fssxp ⊢ g : A ⟶ B → g ⊆ A × B
2 vex ⊢ g ∈ V
3 feq1 ⊢ f = g → f : A ⟶ B ↔ g : A ⟶ B
4 2 3 elab ⊢ g ∈ f | f : A ⟶ B ↔ g : A ⟶ B
5 velpw ⊢ g ∈ 𝒫 A × B ↔ g ⊆ A × B
6 1 4 5 3imtr4i ⊢ g ∈ f | f : A ⟶ B → g ∈ 𝒫 A × B
7 6 ssriv ⊢ f | f : A ⟶ B ⊆ 𝒫 A × B