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Description: The powerclass preserves inclusion (deduction form). (Contributed by BJ, 13-Apr-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | sspwd.1 | ||
| Assertion | sspwd |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sspwd.1 | ||
| 2 | sspw | ||
| 3 | 1 2 | syl |