## Problem 013 — rank:120

**Title:** Cytoskeletal mechanics to cell shape

**Added binding assumptions (LaTeX):**

```latex
Close the force-balance system with $\nabla\cdot v=s_V$ for a specified volumetric source and a complete traction/contact law. The kinematic condition is $V_n=v\cdot n$ only for an impermeable material boundary; with prescribed outward normal permeation velocity $j_w$, use $V_n=v\cdot n+j_w$. Boundary regularity, initial shape, pressure normalization and the solution class are part of the instance.
```

**Direct edits:** 1. **Fresh external checks:** None; supplied sources retained as provenance.