## Problem 151 — rank:152

**Title:** Maintenance of cooperation during major transitions

**Added binding assumptions (LaTeX):**

```latex
Normalize the resident's next-generation operator to neutrality and specify the admissible mutant interval. Excluding invasion by lower-investment mutants is one-sided non-invasibility, not necessarily a full evolutionarily stable strategy or an attracting evolutionary endpoint. Mutants arbitrarily close to the resident may approach neutral growth. Distinguish existence of a resistant high-investment strategy from its accessibility by selection from the stated ancestral population.
```

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