 f-delta = 5.3e-04
 Iter 63: f = 9.721858e-01 f-delta = 4.6e-04
 Iter 64: f = 9.725836e-01 f-delta = 4.0e-04
 Iter 65: f = 9.729269e-01 f-delta = 3.4e-04
 Iter 66: f = 9.732222e-01 f-delta = 3.0e-04
 Iter 67: f = 9.734758e-01 f-delta = 2.5e-04
 Iter 68: f = 9.736930e-01 f-delta = 2.2e-04
 Iter 69: f = 9.738788e-01 f-delta = 1.9e-04
 Iter 70: f = 9.740375e-01 f-delta = 1.6e-04
 Iter 71: f = 9.741730e-01 f-delta = 1.4e-04
 Iter 72: f = 9.742885e-01 f-delta = 1.2e-04
 Iter 73: f = 9.743869e-01 f-delta = 9.8e-0