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Description: A pair containing a set is not empty. (Contributed by FL, 19-Sep-2011) (Proof shortened by JJ, 23-Jul-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | prnzg |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | prid1g | ||
| 2 | 1 | ne0d |