Metamath Proof Explorer


Theorem ffnov

Description: An operation maps to a class to which all values belong. (Contributed by NM, 7-Feb-2004)

Ref Expression
Assertion ffnov F:A×BCFFnA×BxAyBxFyC

Proof

Step Hyp Ref Expression
1 ffnfv F:A×BCFFnA×BwA×BFwC
2 fveq2 w=xyFw=Fxy
3 df-ov xFy=Fxy
4 2 3 eqtr4di w=xyFw=xFy
5 4 eleq1d w=xyFwCxFyC
6 5 ralxp wA×BFwCxAyBxFyC
7 6 anbi2i FFnA×BwA×BFwCFFnA×BxAyBxFyC
8 1 7 bitri F:A×BCFFnA×BxAyBxFyC