User guide

• Mesh views
• Level sets
• Cut results and selections
• Quadrature and output
• Algorithms and scope

The main workflow is:

1. Represent the background mesh as a MeshView.

2. Build one or more named level sets: Pk level sets on that mesh, analytic ones, or level sets made of them.

3. Call cut(mesh, level_set) or cut(mesh, [level_sets...]); parts integrate with quadrays unless you pass backend="lut".

4. Select mesh parts with conditions built from the level sets, such as phi < 0 or (sphere == 0) & (plane < 0), or with their strings, "phi < 0" or "sphere = 0 and plane < 0".

5. Request quadrature rules, visualisation meshes, or VTU output from the selected part.