Metamath Proof Explorer

Theorem reldmoprab

Description: The domain of an operation class abstraction is a relation. (Contributed by NM, 17-Mar-1995)

Ref Expression
Assertion reldmoprab 
|- Rel dom { <. <. x , y >. , z >. | ph }

Proof

Step Hyp Ref Expression
1 dmoprab 
 |-  dom { <. <. x , y >. , z >. | ph } = { <. x , y >. | E. z ph }
2 1 relopabiv 
 |-  Rel dom { <. <. x , y >. , z >. | ph }