FLINT3.7.0-dev

fmpz_mpoly_factor_bound_si

Synopsis#include <flint/fmpz_mpoly_factor.h>
int fmpz_mpoly_factor_bound_si(fmpz_t B, const fmpz_t A, const slong * degs, slong nvars)source

Sets BB to a bound on the coefficients of the divisors of a polynomial ff whose coefficients are bounded by AA in absolute value and whose degrees in its nn = nvars variables are d0,…,dn−1d_0, \ldots, d_{n-1} (degs): B=∣A∣⋅(⌊⌈∏i(di+1)/2n⌉⌋+1)⋅2∑idiB = |A| \cdot (\lfloor \sqrt{\lceil \prod_i (d_i + 1) / 2^{n} \rceil} \rfloor + 1) \cdot 2^{\sum_i d_i}, and B=0B = 0 if some di<0d_i < 0. Returns 0 if the degree sum overflows and 1 otherwise. fmpz_mpolyl_gcd_zippel uses this bound to decide when to give up on a modular reconstruction and start over.

Cite this page

The FLINT team, “fmpz_mpoly_factor_bound_si (fmpz_mpoly_factor.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/fmpz_mpoly_factor/fmpz_mpoly_factor_bound_si.html (generated 2026-11-02).