0 SNES Function norm 3.86571
  1 SNES Function norm 1.3323
  2 SNES Function norm 1.81987e-06
  3 SNES Function norm 1.372e-11
errors on 9 x 9 grid:  av |u-uexact|  = 3.076e-03,  |u-uexact|_inf = 1.334e-02