Metamath Proof Explorer


Theorem pmex

Description: The class of all partial functions from one set to another is a set. (Contributed by NM, 15-Nov-2007)

Ref Expression
Assertion pmex ⊢ A ∈ C ∧ B ∈ D → f | Fun ⁡ f ∧ f ⊆ A × B ∈ V

Proof

Step Hyp Ref Expression
1 ancom ⊢ Fun ⁡ f ∧ f ⊆ A × B ↔ f ⊆ A × B ∧ Fun ⁡ f
2 1 abbii ⊢ f | Fun ⁡ f ∧ f ⊆ A × B = f | f ⊆ A × B ∧ Fun ⁡ f
3 xpexg ⊢ A ∈ C ∧ B ∈ D → A × B ∈ V
4 abssexg ⊢ A × B ∈ V → f | f ⊆ A × B ∧ Fun ⁡ f ∈ V
5 3 4 syl ⊢ A ∈ C ∧ B ∈ D → f | f ⊆ A × B ∧ Fun ⁡ f ∈ V
6 2 5 eqeltrid ⊢ A ∈ C ∧ B ∈ D → f | Fun ⁡ f ∧ f ⊆ A × B ∈ V