<ParameterList name="MueLu">

   <!-- Factory collection -->
  <ParameterList name="Factories">

    <ParameterList name="UncoupledAggregationFact">
      <Parameter name="factory"              type="string" value="UncoupledAggregationFactory"/>
      <Parameter name="aggregation: ordering"                    type="string" value="natural"/>
      <Parameter name="aggregation: max selected neighbors"            type="int"    value="0"/>
      <Parameter name="aggregation: min agg size"           type="int"    value="4"/>
    </ParameterList>

    <ParameterList name="myTentativePFact">
      <Parameter name="factory"                        type="string" value="TentativePFactory"/>
    </ParameterList>
    
  </ParameterList>

  <!-- Definition of the multigrid preconditioner -->
  <ParameterList name="Hierarchy">

    <Parameter name="max levels"                            type="int"      value="10"/>
    <Parameter name="coarse: max size"                      type="int"      value="10"/>
    <Parameter name="verbosity"                             type="string"   value="High"/>

    <ParameterList name="All">
      <Parameter name="Aggregates"           type="string"   value="UncoupledAggregationFact"/>
      <Parameter name="Nullspace"                    type="string"   value="myTentativePFact"/>
      <Parameter name="P"                            type="string"   value="myTentativePFact"/>
      <Parameter name="CoarseSolver"                     type="string"   value="DirectSolver"/>
    </ParameterList>

  </ParameterList>
</ParameterList>
