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