Metamath Proof Explorer


Theorem 1cosscnvxrn

Description: Cosets by the converse range Cartesian product. (Contributed by Peter Mazsa, 19-Apr-2020) (Revised by Peter Mazsa, 21-Sep-2021)

Ref Expression
Assertion 1cosscnvxrn AB-1=A-1B-1

Proof

Step Hyp Ref Expression
1 br1cosscnvxrn xVyVxAB-1yxA-1yxB-1y
2 1 el2v xAB-1yxA-1yxB-1y
3 2 opabbii xy|xAB-1y=xy|xA-1yxB-1y
4 inopab xy|xA-1yxy|xB-1y=xy|xA-1yxB-1y
5 3 4 eqtr4i xy|xAB-1y=xy|xA-1yxy|xB-1y
6 relcoss RelAB-1
7 dfrel4v RelAB-1AB-1=xy|xAB-1y
8 6 7 mpbi AB-1=xy|xAB-1y
9 relcoss RelA-1
10 dfrel4v RelA-1A-1=xy|xA-1y
11 9 10 mpbi A-1=xy|xA-1y
12 relcoss RelB-1
13 dfrel4v RelB-1B-1=xy|xB-1y
14 12 13 mpbi B-1=xy|xB-1y
15 11 14 ineq12i A-1B-1=xy|xA-1yxy|xB-1y
16 5 8 15 3eqtr4i AB-1=A-1B-1