  These pages review two families of mimetic finite difference methods: the
mixed-type methods presented in [Brezzi, Lipnikov, and Simoncini, M3AS, 2005]
and the nodal methods of [Brezzi, Buffa, and Lipnikov, M2AN, 2009]. The purpose
of this exercise it to highlight the similitudes underlying the construction of
the two families. The comparison prompts the definition of a piecewise linear
postprocessing of the nodal mimetic finite difference solution, as it was done
for the mixed-type method in [Cangiani and Manzini, CMAME, 2008].
