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Description: The less-than-or-equal-to relation is a set. (Contributed by SN, 5-Jun-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | leex |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | xrex | ||
| 2 | 1 1 | xpex | |
| 3 | lerelxr | ||
| 4 | 2 3 | ssexi |