utomatically installed by PETSc by configuring with --download-trilinos, --download-hypre, and/or --download-superlu_dist.
  <ul>
    <li><a href="#ML">Nonlinear PDE Example</a> using <a href="http://trilinos.org/packages/ml">Trilinos preconditioner ML</a>
    <li><a href="#HYPRE">Nonlinear PDE Example</a> using BoomerAMG from <a href="https://computation.llnl.gov/projects/hypre-scalable-linear-solvers-multigrid-methods">HYPRE</a>
    <li><a href="#SuperLU">Linear Equation Example</a> using direct solver <a