Quantitative degree control from the plane determinant comparison.
theorem
CCDN.plane_rank_archimedean_error
{s d M : ℕ}
(hd : 0 < d)
(hdM : d ≤ M)
(hr : 2 * s + d ^ 2 = d * (2 * M + 3))
:
For the Hilbert function s of a plane curve of degree d in degree M ≥ d, the archimedean
terms log s! / 2 + (s / 2) log C(M + 2, M) of the determinant comparison are at most
5 s² / 2.
theorem
CCDN.plane_auxiliary_log_degree_bound
{s d M : ℕ}
{B L A K : ℝ}
(hd : 0 < d)
(hdM : d ≤ M)
(hr : 2 * s + d ^ 2 = d * (2 * M + 3))
(hB : 1 ≤ B)
(hL : 1 ≤ L)
(hML : Real.log B ≤ ↑M)
(hheight : Real.log L ≤ 4 * ↑d * Real.log B)
(hcomparison :
↑s ^ 2 / 2 * (Real.log ↑s - 4 * Real.log ↑d - Real.log A - K) ≤ Real.log ↑s.factorial / 2 + ↑s / 2 * Real.log ↑((2 + M).choose M) + ↑s * ↑M * Real.log B - (↑((2 + M).choose M) - ↑s) * Real.log L)
:
The small-height case of the plane auxiliary-degree calculation. The coefficient obstruction is retained with its exact exponent 1/d².
theorem
CCDN.plane_degree_bound_of_log_bound
{d M : ℕ}
{B L A K : ℝ}
(hd : 0 < d)
(hM : 0 < M)
(hB : 0 < B)
(hL : 0 < L)
(hA : 0 < A)
(hlog : Real.log ↑M ≤ K + 23 + Real.log 2 + 3 * Real.log ↑d + Real.log A + 2 / ↑d * Real.log B - Real.log L / ↑d ^ 2)
:
Exponentiation of the logarithmic degree bound, keeping the coefficient saving and the leading box exponent unchanged.