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Description: Bigcup is a function over the universal class. (Contributed by Scott Fenton, 11-Apr-2012)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | fnbigcup |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | fobigcup | ||
| 2 | fofn | ||
| 3 | 1 2 | ax-mp |