∀ (K : Type u_1) [inst : Field K] [inst_1 : NumberField K]
  (I : (FractionalIdeal (nonZeroDivisors (NumberField.RingOfIntegers K)) K)ˣ) (i : Module.Free.ChooseBasisIndex ℤ ↥↑↑I),
  (NumberField.basisOfFractionalIdeal K I) i = ↑((NumberField.fractionalIdealBasis K ↑I) i)