sum of trajectory probabilities = 1.000000000000
max |closed form - enumeration| = 1.67e-16
max |closed form - Hessian|     = 1.11e-16
eigenvalues of F: ['-0.0000', '0.0000', '0.0000', '0.0838', '0.2128', '0.6653'] (three zeros: adding a constant to a state's logits changes nothing)

     |d|     KL exact  (1/2) d^T F d    ratio
  1.3907    1.155e-01      1.130e-01   1.0220
  0.4172    1.028e-02      1.017e-02   1.0112
  0.1391    1.135e-03      1.130e-03   1.0042
  0.0417    1.018e-04      1.017e-04   1.0013
  0.0139    1.130e-05      1.130e-05   1.0004
