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