Thank you: "restriction" refers to the element, not the mesh.
What I really want to do is generate a mesh consisting of the facets of an existing mesh, and then put a DG0 element on it. (In 2D, this mesh will consist of 1D elements positioned in 2D.) Is that possible? If so, can functions on this facet-only-mesh be used in the *dS portion of a form that involves things like the jump in a 2D trial or test function?
My application is an interior penalty method involving spatially-variable but geometrically-determined coefficients defined on facets.
