enter image description here when we use the fenics, that shows "AttributeError: type object 'dolfin.cpp.MPI' has no attribute 'process_number' ".
How we solve it? And I intend to carry out the code. Here, the code is Link to file :https://fenicsproject.org/olddocs/dolfin//1.3.0/python/demo/documented/cahn-hilliard/python/documentation.html