This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Metamath Proof Explorer
Description: The image of the double converse of a class. (Contributed by NM, 8-Apr-2007)
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|
Ref |
Expression |
|
Assertion |
imacnvcnv |
|
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
rescnvcnv |
|
| 2 |
1
|
rneqi |
|
| 3 |
|
df-ima |
|
| 4 |
|
df-ima |
|
| 5 |
2 3 4
|
3eqtr4i |
|