Starting with polynomial:
P : t^4 - 6*t^2 + 3
Extension levels are: 4 9
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Trying to find an order 9 Kronrod extension for:
P1 : t^4 - 6*t^2 + 3
Solvable: 1
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Ending with final polynomial:
P : t^13 - 66*t^11 + 7569/5*t^9 - 74484/5*t^7 + 314307/5*t^5 - 98658*t^3 + 37611*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:
| (-3.2290040429144049805 - 1.0753375999518608481e-148j)  +/-  (7.75e-61, 7.75e-61j)
| (-4.2283965787258560516 - 1.9578144419400542701e-154j)  +/-  (8.47e-61, 8.47e-61j)
| (5.4228479113280690393 - 4.6614629570001292146e-156j)  +/-  (2.92e-61, 2.92e-61j)
| (3.2290040429144049805 - 3.1296443192749890967e-159j)  +/-  (8.09e-61, 8.09e-61j)
| (-5.4228479113280690393 - 4.2676967990113487682e-160j)  +/-  (3.66e-61, 3.66e-61j)
| (4.2283965787258560516 - 5.3346209987641859603e-161j)  +/-  (7.37e-61, 7.37e-61j)
| (2.3344142183389772393 + 5.6902623986817983576e-160j)  +/-  (4.37e-61, 4.37e-61j)
| (-0.74196378430272585765 - 4.6886317371950853166e-163j)  +/-  (8.98e-63, 8.98e-63j)
| (-1.5122552015009576337 - 1.0188800022119531165e-171j)  +/-  (8.7e-62, 8.7e-62j)
| (1.5122552015009576337 + 6.2384920770356132348e-175j)  +/-  (8.24e-62, 8.24e-62j)
| (0.74196378430272585765 + 1.5037899958241996895e-178j)  +/-  (8.98e-63, 8.98e-63j)
| (0 + 0j)  +/-  (0, 0j)
| (-2.3344142183389772393 + 1.8728839652171412693e-196j)  +/-  (3.79e-61, 3.79e-61j)
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The weights are:
| (0.0020400873151785245963 - 4.393459396803514875e-151j)  +/-  (5.95e-23, 2.39e-53j)
| (5.6054897269886972384e-05 - 2.5107500225288346744e-152j)  +/-  (1.99e-24, 8e-55j)
| (2.2484137339454061401e-07 - 1.2402059350046067667e-154j)  +/-  (7.51e-27, 3.02e-57j)
| (0.0020400873151785245963 - 3.3969944450355684673e-152j)  +/-  (8.75e-25, 3.52e-55j)
| (2.2484137339454061401e-07 + 4.8909925444567020102e-154j)  +/-  (4.93e-27, 1.97e-57j)
| (5.6054897269886972384e-05 + 3.364739633989001618e-153j)  +/-  (6.73e-26, 2.71e-56j)
| (0.022355432077313433504 + 1.8594829479536357828e-151j)  +/-  (3.07e-24, 1.23e-54j)
| (0.22772324146103540239 + 2.2506773326280423436e-150j)  +/-  (2.37e-23, 1.08e-53j)
| (0.1008041410302270608 - 1.7444398264518591395e-150j)  +/-  (6.58e-24, 2.65e-54j)
| (0.1008041410302270608 - 6.3163911514922586955e-151j)  +/-  (5.01e-24, 2.13e-54j)
| (0.22772324146103540239 + 1.4096122574452944171e-150j)  +/-  (9.32e-24, 4.22e-54j)
| (0.2940416367552045944 - 2.1318705612757597353e-150j)  +/-  (4.52e-24, 2.5e-54j)
| (0.022355432077313433504 + 1.1564051840692057132e-150j)  +/-  (9.62e-25, 3.55e-55j)
