Metamath Proof Explorer


Theorem relrpss

Description: The proper subset relation is a relation. (Contributed by Stefan O'Rear, 2-Nov-2014)

Ref Expression
Assertion relrpss Rel []

Proof

Step Hyp Ref Expression
1 df-rpss [] = { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝑥𝑦 }
2 1 relopabiv Rel []