Starting with polynomial:
P : t^4 - 6*t^2 + 3
Extension levels are: 4 11
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Trying to find an order 11 Kronrod extension for:
P1 : t^4 - 6*t^2 + 3
Solvable: 1
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Ending with final polynomial:
P : t^15 - 641/6*t^13 + 29116/7*t^11 - 1045605/14*t^9 + 4515555/7*t^7 - 5082165/2*t^5 + 3863970*t^3 - 2916045/2*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
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The nodes are:
| (-5.2223117617903654322 - 2.6590166107900559153e-147j)  +/-  (3.44e-60, 3.44e-60j)
| (2.3344142183389772393 + 1.0401447330443454021e-146j)  +/-  (4.88e-61, 4.88e-61j)
| (5.2223117617903654322 + 4.3245994229981667518e-158j)  +/-  (2.91e-60, 2.91e-60j)
| (3.2073341618684212087 - 2.0701054013195237922e-169j)  +/-  (2.16e-60, 2.16e-60j)
| (4.1533469233083435108 + 6.4954871364101173486e-182j)  +/-  (3.45e-60, 3.45e-60j)
| (-3.2073341618684212087 - 9.929282109453491249e-187j)  +/-  (2.11e-60, 2.11e-60j)
| (-1.5154507704216881063 - 3.4474180199187528387e-187j)  +/-  (8.68e-62, 8.68e-62j)
| (1.1491393399729176129e-187 + 3.5910604374153675403e-188j)  +/-  (1.81e-186, 1.81e-186j)
| (6.612633292961629502 + 2.2444127733846047127e-189j)  +/-  (9.52e-61, 9.52e-61j)
| (-0.74196378430272585765 - 7.2603684685903350692e-193j)  +/-  (1.15e-62, 1.15e-62j)
| (0.74196378430272585765 - 5.2603424376201672954e-192j)  +/-  (9.49e-63, 9.49e-63j)
| (-6.612633292961629502 - 1.0124756368884517883e-199j)  +/-  (9.03e-61, 9.03e-61j)
| (1.5154507704216881063 + 0j)  +/-  (9.47e-62, 9.47e-62j)
| (-4.1533469233083435108 - 8.970475455987810782e-203j)  +/-  (3.15e-60, 3.15e-60j)
| (-2.3344142183389772393 - 2.232651669045855128e-202j)  +/-  (5.33e-61, 5.33e-61j)
-------------------------------------------------
The weights are:
| (5.5644129458151343998e-07 + 1.0578420632159009488e-151j)  +/-  (4.46e-22, 6.5e-52j)
| (0.022077688383356701295 - 3.1678060527188453371e-148j)  +/-  (1.42e-17, 2.07e-47j)
| (5.5644129458151343998e-07 - 2.8700116355564954463e-151j)  +/-  (1.19e-22, 1.73e-52j)
| (0.0021068104520711942068 - 6.8972425235670409243e-149j)  +/-  (5.1e-20, 7.43e-50j)
| (7.1244098289090788501e-05 + 5.3967636554832349925e-150j)  +/-  (2.03e-21, 2.96e-51j)
| (0.0021068104520711942068 + 1.0808968373110518817e-149j)  +/-  (3.15e-22, 4.59e-52j)
| (0.10059572433770356288 + 1.5287705257272438568e-148j)  +/-  (1.42e-19, 2.07e-49j)
| (0.29346989795131027519 + 5.411912386468844354e-148j)  +/-  (4.63e-19, 6.73e-49j)
| (2.3455116499489024503e-10 + 4.9426634146796831522e-153j)  +/-  (2.97e-25, 4.32e-55j)
| (0.22841302707707856673 - 3.3874507141822836241e-148j)  +/-  (2.09e-19, 3.03e-49j)
| (0.22841302707707856673 - 6.5489629895544070518e-148j)  +/-  (1.24e-19, 1.81e-49j)
| (2.3455116499489024503e-10 - 2.3890603607415174815e-153j)  +/-  (2.96e-26, 4.31e-56j)
| (0.10059572433770356288 + 7.1983892431366859945e-148j)  +/-  (1.64e-20, 2.39e-50j)
| (7.1244098289090788501e-05 - 1.4961369888794839204e-150j)  +/-  (1.11e-23, 1.62e-53j)
| (0.022077688383356701295 - 4.9043746337587558592e-149j)  +/-  (4.3e-22, 6.12e-52j)
