Metamath Proof Explorer


Theorem funimaexg

Description: Axiom of Replacement using abbreviations. Axiom 39(vi) of Quine p. 284. Compare Exercise 9 of TakeutiZaring p. 29. (Contributed by NM, 10-Sep-2006) Shorten proof and avoid ax-10 , ax-12 . (Revised by SN, 19-Dec-2024)

Ref Expression
Assertion funimaexg ⊢ Fun ⁡ A ∧ B ∈ C → A B ∈ V

Proof

Step Hyp Ref Expression
1 dffun6 ⊢ Fun ⁡ A ↔ Rel ⁡ A ∧ ∀ x ∃* y x A y
2 1 simprbi ⊢ Fun ⁡ A → ∀ x ∃* y x A y
3 dfima2 ⊢ A B = y | ∃ x ∈ B x A y
4 axrep6g ⊢ B ∈ C ∧ ∀ x ∃* y x A y → y | ∃ x ∈ B x A y ∈ V
5 3 4 eqeltrid ⊢ B ∈ C ∧ ∀ x ∃* y x A y → A B ∈ V
6 2 5 sylan2 ⊢ B ∈ C ∧ Fun ⁡ A → A B ∈ V
7 6 ancoms ⊢ Fun ⁡ A ∧ B ∈ C → A B ∈ V