Metamath Proof Explorer


Theorem cnvcosseq

Description: The converse of cosets by R are cosets by R . (Contributed by Peter Mazsa, 3-May-2019)

Ref Expression
Assertion cnvcosseq R -1 = R

Proof

Step Hyp Ref Expression
1 brcosscnvcoss x V y V x R y y R x
2 1 el2v x R y y R x
3 2 biimpi x R y y R x
4 3 gen2 x y x R y y R x
5 cnvsym R -1 R x y x R y y R x
6 4 5 mpbir R -1 R
7 relcoss Rel R
8 relcnveq Rel R R -1 R R -1 = R
9 7 8 ax-mp R -1 R R -1 = R
10 6 9 mpbi R -1 = R