+
+expected_A = [1, 0, 0, 0, 0; ...
+ 16, -32, 16, 0, 0; ...
+ 0, 16, -32, 16, 0; ...
+ 0, 0, 16, -32, 16; ...
+ 0, 0, 0, 0, 1];
+unit_test_equals("Homework #1 problem #1 Poisson matrix is correct", ...
+ true, ...
+ expected_A == poisson_matrix(4, 0, 1));