Description: Inverse point images under functions expressed as abstractions. (Contributed by Stefan O'Rear, 1-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | fniniseg2 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fncnvima2 | ||
2 | fvex | ||
3 | 2 | elsn | |
4 | 3 | rabbii | |
5 | 1 4 | eqtrdi |