This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: An operation maps to a class to which all values belong. (Contributed by NM, 7-Feb-2004)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ffnov |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ffnfv | ||
| 2 | fveq2 | ||
| 3 | df-ov | ||
| 4 | 2 3 | eqtr4di | |
| 5 | 4 | eleq1d | |
| 6 | 5 | ralxp | |
| 7 | 6 | anbi2i | |
| 8 | 1 7 | bitri |