  <p>
      Trilinos (via its Amesos package) can interface with a number of direct
      solvers (see, for example,
      <a href="https://trilinos.org/docs/r11.8/packages/amesos/doc/html/index.html"
	 target="_top">this page for Trilinos 11.8</a>). Most of them are external
      packages to Trilinos and you will need to tell Trilinos configuration
      scripts that you want to use them, for example via the
      <code>TrilinosWrappers::SolverDirect</code> class.  This can be tricky,
      but adding def