## Problem 273 — rank:112

**Title:** Spatial confinement of gene drives

**Added binding assumptions (LaTeX):**

```latex
Define the regional average using a declared density weighting and exclude or explicitly encode empty populations. The external supremum needs a fixed spatial resolution or a regular continuous frequency field; microscopic frequencies in nearly empty patches can otherwise dominate it. Specify demographic and environmental randomness or use deterministic worst-case reachability. The target event is measured at the declared time unless an alternative sustained-entry criterion is explicitly adopted.
```

**Direct edits:** 0. **Fresh external checks:** None; supplied sources retained as provenance.