Starting with polynomial:
P : 256*t^8 - 3584*t^6 + 13440*t^4 - 13440*t^2 + 1680
Extension levels are: 8 11
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Trying to find an order 11 Kronrod extension for:
P1 : 256*t^8 - 3584*t^6 + 13440*t^4 - 13440*t^2 + 1680
Solvable: 1
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Ending with final polynomial:
P : 256*t^19 - 19308928/1347*t^17 + 418651520/1347*t^15 - 1521292480/449*t^13 + 9071700160/449*t^11 - 30031939520/449*t^9 + 52723966680/449*t^7 - 43021232100/449*t^5 + 12604959675/449*t^3 - 2144332575/898*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: 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:   15 out of 19
Indefinite weights: 0 out of 19
Negative weights:   4 out of 19
Extension rule has valid weights: 0
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*** EXTENSION WITH INVALID WEIGHTS ***
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