Metamath Proof Explorer


Theorem imacnvcnv

Description: The image of the double converse of a class. (Contributed by NM, 8-Apr-2007)

Ref Expression
Assertion imacnvcnv A -1 -1 B = A B

Proof

Step Hyp Ref Expression
1 rescnvcnv A -1 -1 B = A B
2 1 rneqi ran A -1 -1 B = ran A B
3 df-ima A -1 -1 B = ran A -1 -1 B
4 df-ima A B = ran A B
5 2 3 4 3eqtr4i A -1 -1 B = A B