Metamath Proof Explorer


Theorem br1cossxrnres

Description: <. B , C >. and <. D , E >. are cosets by an intersection with a restriction: a binary relation. (Contributed by Peter Mazsa, 8-Jun-2021)

Ref Expression
Assertion br1cossxrnres B V C W D X E Y B C R S A D E u A u S C u R B u S E u R D

Proof

Step Hyp Ref Expression
1 xrnres2 R S A = R S A
2 1 cosseqi R S A = R S A
3 2 breqi B C R S A D E B C R S A D E
4 opex B C V
5 opex D E V
6 br1cossres B C V D E V B C R S A D E u A u R S B C u R S D E
7 4 5 6 mp2an B C R S A D E u A u R S B C u R S D E
8 brxrn u V B V C W u R S B C u R B u S C
9 8 el3v1 B V C W u R S B C u R B u S C
10 brxrn u V D X E Y u R S D E u R D u S E
11 10 el3v1 D X E Y u R S D E u R D u S E
12 9 11 bi2anan9 B V C W D X E Y u R S B C u R S D E u R B u S C u R D u S E
13 an2anr u R B u S C u R D u S E u S C u R B u S E u R D
14 12 13 syl6bb B V C W D X E Y u R S B C u R S D E u S C u R B u S E u R D
15 14 rexbidv B V C W D X E Y u A u R S B C u R S D E u A u S C u R B u S E u R D
16 7 15 syl5bb B V C W D X E Y B C R S A D E u A u S C u R B u S E u R D
17 3 16 bitr3id B V C W D X E Y B C R S A D E u A u S C u R B u S E u R D