Metamath Proof Explorer


Theorem relwdom

Description: Weak dominance is a relation. (Contributed by Stefan O'Rear, 11-Feb-2015)

Ref Expression
Assertion relwdom
|- Rel ~<_*

Proof

Step Hyp Ref Expression
1 df-wdom
 |-  ~<_* = { <. x , y >. | ( x = (/) \/ E. z z : y -onto-> x ) }
2 1 relopabiv
 |-  Rel ~<_*