Starting with polynomial:
P : 2*t
Extension levels are: 1 2 6 14
-------------------------------------------------
Trying to find an order 2 Kronrod extension for:
P1 : 2*t
Solvable: 1
-------------------------------------------------
Trying to find an order 6 Kronrod extension for:
P2 : 2*t^3 - 3*t
Solvable: 1
-------------------------------------------------
Trying to find an order 14 Kronrod extension for:
P3 : 2*t^9 - 117/4*t^7 + 945/8*t^5 - 2205/16*t^3 + 945/32*t
Solvable: 1
-------------------------------------------------
Ending with final polynomial:
P : 2*t^23 - 3852927458237/20406027900*t^21 + 200673176311657/27208037200*t^19 - 8516201417318679/54416074400*t^17 + 86648979975626579/43532859520*t^15 - 274821978930204615/17413143808*t^13 + 2738115730067306589/34826287616*t^11 - 84416696594777760213/348262876160*t^9 + 310835630853592445601/696525752320*t^7 - 128055455760565021689/278610300928*t^5 + 127735463726273808405/557220601856*t^3 - 40420437771237240717/1114441203712*t
-------------------------------------------------
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:   19 out of 23
Indefinite weights: 0 out of 23
Negative weights:   4 out of 23
Extension rule has valid weights: 0
**************************************
*** EXTENSION WITH INVALID WEIGHTS ***
**************************************
