Starting with polynomial:
P : t
Extension levels are: 1 12
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Trying to find an order 12 Kronrod extension for:
P1 : t
Solvable: 1
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Ending with final polynomial:
P : t^13 - 78*t^11 + 2145*t^9 - 25740*t^7 + 135135*t^5 - 270270*t^3 + 135135*t
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Computing nodes and weights
  current precision for roots: 53
  current precision for roots: 106
 current precision for weights: 53
Linear system for weights solvable: 1
  current precision for roots: 106
  current precision for roots: 212
 current precision for weights: 106
Linear system for weights solvable: 1
Sufficient bits for target precision reached
Positive weights:   13 out of 13
Indefinite weights: 0 out of 13
Negative weights:   0 out of 13
Extension rule has valid weights: 1
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The nodes are:
| (4.5913984489365206271 + 4.017397398342840147e-133j)  +/-  (9.39e-61, 9.39e-61j)
| (-5.8001672523865003059 + 2.2840778765728101756e-137j)  +/-  (3.11e-61, 3.11e-61j)
| (-4.5913984489365206271 + 9.3847645086707855833e-148j)  +/-  (9.39e-61, 9.39e-61j)
| (2.6206899734322147806 + 1.2859993021020864288e-157j)  +/-  (2.61e-61, 2.61e-61j)
| (-3.5634443802816340916 + 6.104989241139434006e-166j)  +/-  (9.85e-61, 9.85e-61j)
| (3.5634443802816340916 + 9.3154743059378570649e-171j)  +/-  (7.75e-61, 7.75e-61j)
| (5.8001672523865003059 + 2.7145337360518886702e-177j)  +/-  (3.42e-61, 3.42e-61j)
| (-0.8566794935194500339 + 1.0543399409825118015e-181j)  +/-  (8.2e-63, 8.2e-63j)
| (-2.6206899734322147806 + 1.3495551244576151059e-179j)  +/-  (2.64e-61, 2.64e-61j)
| (0.8566794935194500339 + 8.2370307889258734493e-184j)  +/-  (9.48e-63, 9.48e-63j)
| (1.7254183795882391615 - 3.0299572440692163622e-189j)  +/-  (8.71e-62, 8.71e-62j)
| (4.3836186980168060795e-193 + 7.0137899168268897272e-192j)  +/-  (9.14e-191, 9.14e-191j)
| (-1.7254183795882391615 + 5.4795233725210075994e-194j)  +/-  (6.21e-62, 6.21e-62j)
-------------------------------------------------
The weights are:
| (1.1526596527333874013e-05 - 1.0630677012106050706e-137j)  +/-  (9.36e-26, 3.21e-56j)
| (2.7226276428059033082e-08 + 2.1659311136523532587e-140j)  +/-  (2.77e-27, 9.51e-58j)
| (1.1526596527333874013e-05 - 5.0428961309699840423e-139j)  +/-  (3.27e-26, 1.12e-56j)
| (0.011770560505996535835 - 7.5088219824503822292e-137j)  +/-  (1.49e-24, 5.12e-55j)
| (0.00068123635044292719588 + 4.3654902901850504029e-138j)  +/-  (1.18e-25, 4.06e-56j)
| (0.00068123635044292719588 + 3.4631449433991235097e-137j)  +/-  (7.25e-26, 2.49e-56j)
| (2.7226276428059033082e-08 - 1.8618560337518418095e-139j)  +/-  (2.47e-28, 8.46e-59j)
| (0.23787152296413627089 - 1.2210250580851883559e-136j)  +/-  (1.71e-24, 6.63e-55j)
| (0.011770560505996535835 - 2.0518026728340525054e-137j)  +/-  (1.12e-25, 3.86e-56j)
| (0.23787152296413627089 - 1.7811861670390275092e-136j)  +/-  (7.39e-25, 2.88e-55j)
| (0.079168955860450007974 + 1.3390601613884725832e-136j)  +/-  (4.16e-25, 1.56e-55j)
| (0.34099234099234099234 + 1.734696965376815375e-136j)  +/-  (3.81e-25, 1.67e-55j)
| (0.079168955860450007974 + 6.0754209582002562303e-137j)  +/-  (2.97e-25, 9.26e-56j)
