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Description: The base set of a restriction to A is a subset of A . (Contributed by SN, 10-Jan-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | ressbasss2.r | ||
| Assertion | ressbasss2 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ressbasss2.r | ||
| 2 | eqid | ||
| 3 | 1 2 | ressbasssg | |
| 4 | inss1 | ||
| 5 | 3 4 | sstri |