Metamath Proof Explorer


Theorem elmpocl2

Description: If a two-parameter class is not empty, the second argument is in its nominal domain. (Contributed by FL, 15-Oct-2012) (Revised by Stefan O'Rear, 7-Mar-2015)

Ref Expression
Hypothesis elmpocl.f F=xA,yBC
Assertion elmpocl2 XSFTTB

Proof

Step Hyp Ref Expression
1 elmpocl.f F=xA,yBC
2 1 elmpocl XSFTSATB
3 2 simprd XSFTTB