Metamath Proof Explorer


Theorem brnonrel

Description: A non-relation cannot relate any two classes. (Contributed by RP, 23-Oct-2020)

Ref Expression
Assertion brnonrel X U Y V ¬ X A A -1 -1 Y

Proof

Step Hyp Ref Expression
1 br0 ¬ Y X
2 brcnvg Y V X U Y A A -1 -1 -1 X X A A -1 -1 Y
3 2 ancoms X U Y V Y A A -1 -1 -1 X X A A -1 -1 Y
4 cnvnonrel A A -1 -1 -1 =
5 4 breqi Y A A -1 -1 -1 X Y X
6 3 5 bitr3di X U Y V X A A -1 -1 Y Y X
7 1 6 mtbiri X U Y V ¬ X A A -1 -1 Y