Metamath Proof Explorer


Theorem cnvimarndm

Description: The preimage of the range of a class is equal to the domain of the class. (Contributed by Jeff Hankins, 15-Jul-2009) (Proof shortened by BJ, 29-Sep-2026)

Ref Expression
Assertion cnvimarndm ⊢ A -1 ran ⁡ A = dom ⁡ A

Proof

Step Hyp Ref Expression
1 ssid ⊢ ran ⁡ A ⊆ ran ⁡ A
2 cnvimassrndm ⊢ ran ⁡ A ⊆ ran ⁡ A → A -1 ran ⁡ A = dom ⁡ A
3 1 2 ax-mp ⊢ A -1 ran ⁡ A = dom ⁡ A