PROBLEM11, Mitchell's "intersecting interfaces" problem, on the [-1,+1]x[-1,+1] square.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
The DEAL.II implementations of these problems was done by Lukas Bystricky, of the Department of Scientific Computing, Florida State University.
You can go up one level to the MITCHELL_DEALII directory.