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 [C.]

Proof

Step Hyp Ref Expression
1 df-rpss 
 |-  [C.] = { <. x , y >. | x C. y }
2 1 relopabiv 
 |-  Rel [C.]