   alias -sd -start_in_debugger
   alias -ed -on_error_attach_debugger

  -mat_partitioning_type  square

  -mat_type               is
  -pc_type                nn

#  -show_grid
#  -draw_pause             -1
#  -show_solution

#  -localD_ksp_monitor
#  -localD_ksp_type        cg
#  -localD_ksp_rtol        1.e-11
#  -localD_ksp_atol        1.e-5
#  -localD_pc_type         lu

#  -localN_ksp_truemonitor
#  -localN_ksp_type        gmres
#  -localN_ksp_max_it      2
#  -localN_ksp_rtol        1.e-11
#  -localN_ksp_atol        1.e-5
#  -localN_pc_type         lu

# DAMPING and NULLSPACE options. Default is damping (with 1.e-12) and removing nullspace of FLOATING subdomains ONLY.
#  -localN_pc_nn_damp_fixed [value]
#  -localN_pc_nn_remove_nullspace_fixed
#  -localN_pc_nn_set_damping_factor_floating [value]
#  -localN_pc_nn_not_damp_floating
#  -localN_pc_nn_not_remove_nullspace_floating

  -ksp_monitor
  -ksp_compute_eigenvalues
  -ksp_rtol                1.e-12

#  -log_summary
#  -log_sync

#  -enforce_preserving_constants

#  -save_coarse_matrix
#  -save_global_preconditioner

#  -turn_off_first_balancing
#  -turn_off_second_balancing

#  -check_consistency

#  -bc_pf_type              constant 
#  -bc_pf_constant          1.0
#  -bc_pf_type              string 
#  -bc_pf_constant          f=1.0

#  -rhs_pf_type             constant 
#  -rhs_pf_constant         0.0



