## Problem 186 — rank:167

**Title:** Quantitative theory of mutualism

**Added binding assumptions (LaTeX):**

```latex
Evaluate the Jacobian in all density and resource coordinates and require a physically feasible resource equilibrium. A negative spectral abscissa establishes local asymptotic stability under smoothness, while the basin inclusion is an additional global claim. Specify whether a benefit sign is the direct growth-rate contribution or its density derivative; a positive net mutualistic benefit and a positive marginal interaction are not interchangeable.
```

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