Description: A member in a half-open integer interval is greater than or equal to the lower bound. (Contributed by Stefan O'Rear, 15-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elfzole1 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elfzoelz | ||
| 2 | elfzoel1 | ||
| 3 | elfzoel2 | ||
| 4 | elfzo | ||
| 5 | 1 2 3 4 | syl3anc | |
| 6 | 5 | ibi | |
| 7 | 6 | simpld |