Metamath Proof Explorer


Theorem brne0

Description: If two sets are in a binary relation, the relation cannot be empty. (Contributed by Alexander van der Vekens, 7-Jul-2018)

Ref Expression
Assertion brne0 ⊢ A R B → R ≠ ∅

Proof

Step Hyp Ref Expression
1 df-br ⊢ A R B ↔ A B ∈ R
2 ne0i ⊢ A B ∈ R → R ≠ ∅
3 1 2 sylbi ⊢ A R B → R ≠ ∅