## Problem 051 — rank:320

**Title:** Robust perfect adaptation

**Added binding assumptions (LaTeX):**

```latex
Exclude the vacuous output $h\equiv y_0$ and require genuine open-loop disturbance sensitivity. Separate fixed reference/setpoint parameters from uncertain nuisance rates: a setpoint determined by a ratio of controller rates cannot stay fixed when both rates vary independently. The uncertainty set must respect the intended reference calibration. Exact adaptation, approximate adaptation under leakage, and finite-horizon tracking are different targets.
```

**Direct edits:** 0. **Fresh external checks:** SC02