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Description: Condition necessary for zero element to exist. (Contributed by NM, 14-Sep-2018)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | atl01dm.b | ||
| atl01dm.u | |||
| atl01dm.g | |||
| Assertion | atl0dm |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | atl01dm.b | ||
| 2 | atl01dm.u | ||
| 3 | atl01dm.g | ||
| 4 | eqid | ||
| 5 | eqid | ||
| 6 | eqid | ||
| 7 | 1 3 4 5 6 | isatl | |
| 8 | 7 | simp2bi |