Starting with polynomial:
P : t^2 - 1
Extension levels are: 2 20
-------------------------------------------------
Trying to find an order 20 Kronrod extension for:
P1 : t^2 - 1
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : t^22 - 1181590807/5060457*t^20 + 113450524465/5060457*t^18 - 649682892835/562273*t^16 + 19694384411050/562273*t^14 - 362148733074310/562273*t^12 + 4024456368542610/562273*t^10 - 26133921471007350/562273*t^8 + 92387182004842725/562273*t^6 - 155509398101932875/562273*t^4 + 94224095717476725/562273*t^2 - 8649322961253975/562273
-------------------------------------------------
Computing nodes and weights
  current precision for roots: 53
  current precision for roots: 106
 current precision for weights: 53
Linear system for weights solvable: 0
  current precision for roots: 106
  current precision for roots: 212
 current precision for weights: 106
Linear system for weights solvable: 1
  current precision for roots: 212
  current precision for roots: 424
 current precision for weights: 212
Linear system for weights solvable: 1
Sufficient bits for target precision reached
Positive weights:   22 out of 22
Indefinite weights: 0 out of 22
Negative weights:   0 out of 22
Extension rule has valid weights: 1
-------------------------------------------------
The nodes are:
| (-2.3532617193700997362 + 1.151329441018364284e-373j)  +/-  (8.17e-124, 8.17e-124j)
| (-1 + 1.0397170271293192249e-376j)  +/-  (1.51e-125, 1.51e-125j)
| (2.3532617193700997362 + 4.5572625871175193132e-379j)  +/-  (8.77e-124, 8.77e-124j)
| (-5.2749131231106767794 + 8.7143383038175663226e-387j)  +/-  (4.41e-122, 4.41e-122j)
| (3.7602455005259023482 - 3.5792799460892673755e-393j)  +/-  (1.44e-122, 1.44e-122j)
| (8.1204403159369693153 - 4.324999678509660087e-395j)  +/-  (3.71e-123, 3.71e-123j)
| (-3.047427742808632157 - 1.9210666585650989742e-393j)  +/-  (3.71e-123, 3.71e-123j)
| (7.0242756563279622323 - 4.9921960078769240728e-398j)  +/-  (1.83e-122, 1.83e-122j)
| (-6.105308445701344896 - 1.2617162052493427895e-399j)  +/-  (4.03e-122, 4.03e-122j)
| (3.047427742808632157 + 8.5452573862169873433e-405j)  +/-  (4.2e-123, 4.2e-123j)
| (5.2749131231106767794 - 7.1973447627958554112e-405j)  +/-  (4.46e-122, 4.46e-122j)
| (4.4991245811000041365 + 2.2628798449503643241e-406j)  +/-  (3e-122, 3e-122j)
| (-7.0242756563279622323 - 9.9245630217991656854e-408j)  +/-  (2e-122, 2e-122j)
| (-8.1204403159369693153 - 2.2797474532947638066e-416j)  +/-  (3.92e-123, 3.92e-123j)
| (-4.4991245811000041365 - 2.2589810834976653975e-424j)  +/-  (2.95e-122, 2.95e-122j)
| (-0.33278598572612987549 + 5.1935382058518032974e-432j)  +/-  (9.43e-127, 9.43e-127j)
| (1.6722472893031764503 + 1.8867664114929968941e-431j)  +/-  (1.29e-124, 1.29e-124j)
| (-3.7602455005259023482 - 1.6788605307840560343e-431j)  +/-  (1.51e-122, 1.51e-122j)
| (-1.6722472893031764503 + 8.5065245781665834763e-435j)  +/-  (1.32e-124, 1.32e-124j)
| (6.105308445701344896 + 5.3629725266536670885e-436j)  +/-  (3.84e-122, 3.84e-122j)
| (1 + 2.2959775505875416908e-442j)  +/-  (1.64e-125, 1.64e-125j)
| (0.33278598572612987549 + 1.017644216432290614e-442j)  +/-  (7.36e-127, 7.36e-127j)
-------------------------------------------------
The weights are:
| (0.017187176300694859707 + 2.3035534316070738211e-375j)  +/-  (7.1e-37, 5.71e-98j)
| (0.16191362529710347104 + 4.4518848160253836839e-375j)  +/-  (9.48e-37, 7.62e-98j)
| (0.017187176300694859707 - 4.2210108343406333753e-376j)  +/-  (2.38e-37, 1.92e-98j)
| (2.8943441332544042102e-07 - 2.9336880747977327712e-378j)  +/-  (9.84e-45, 7.92e-106j)
| (0.00024577897477210527533 - 3.9609016479777509296e-377j)  +/-  (6.36e-42, 5.12e-103j)
| (2.4086304852037063482e-15 + 8.294890733430051158e-383j)  +/-  (2.68e-49, 2.16e-110j)
| (0.0026972386873166130665 + 1.1398728337437587399e-375j)  +/-  (2.21e-41, 1.78e-102j)
| (7.5782259317752692974e-12 - 4.9533098808196552294e-381j)  +/-  (4.9e-48, 3.94e-109j)
| (2.784090915321282171e-09 + 2.2948932657432620599e-379j)  +/-  (1.56e-47, 1.26e-108j)
| (0.0026972386873166130665 + 1.4691452775815749427e-376j)  +/-  (5.66e-42, 4.55e-103j)
| (2.8943441332544042102e-07 - 1.1252868717593907836e-378j)  +/-  (3.04e-46, 2.44e-107j)
| (1.2117273993931316208e-05 + 7.9585927739699053762e-378j)  +/-  (6.17e-45, 4.96e-106j)
| (7.5782259317752692974e-12 - 9.9334214074922024366e-381j)  +/-  (2.51e-50, 2.02e-111j)
| (2.4086304852037063482e-15 + 1.5050097129245053397e-382j)  +/-  (4.61e-52, 3.71e-113j)
| (1.2117273993931316208e-05 + 2.5369603233711765331e-377j)  +/-  (1.14e-47, 9.2e-109j)
| (0.2513241347585130496 - 3.7321620040785261195e-375j)  +/-  (2.6e-44, 2e-105j)
| (0.06661963648152109467 + 9.6603270614799994451e-376j)  +/-  (1.75e-45, 1.36e-106j)
| (0.00024577897477210527533 - 1.7173668657345461618e-376j)  +/-  (5.25e-47, 4.22e-108j)
| (0.06661963648152109467 - 5.6700301245155080951e-375j)  +/-  (1.39e-45, 1.11e-106j)
| (2.784090915321282171e-09 + 1.0192554138754317285e-379j)  +/-  (7.72e-50, 6.41e-111j)
| (0.16191362529710347104 - 1.8016930395927091459e-375j)  +/-  (2.25e-45, 1.61e-106j)
| (0.2513241347585130496 + 2.7994876567439884083e-375j)  +/-  (3e-45, 2.08e-106j)
