fact: Definition greatest_series_x_power : ∀ α (R : ring α) (K : field R), power_series α → nat → nat := λ (α : Type) (R : ring α) (K : field R) (s : power_series α) (n : nat), let u := nth_series_order K s n in let v := sequence_gcd_upto u in let w := sequence_diff v in let t := sequence_all_zero_from w in match LPO t with | inl _ => O | inr (exist _ i _) => v i end.
imports: Utf8 QArith NPeano Misc NbarM Field2 Power_series