[Libmesh-users] question about surface elements

[Michael P. <mpo...@pu...>]

Dear Libmesh developers,
I see from the examples that the surface element is constructed as follows:

// Declare a special finite element object for
// boundary integration.
std::unique_ptr<FEBase> fe_face (FEBase::build(dim, fe_type));

Question: why the dimension is equal to the dimension of the mesh 
instead of dim - 1, as you use in the quadrature rule?
Thank you.