qqbar_sgn_re, qqbar_sgn_im
Synopsis
#include <flint/qqbar.h>A sign is read off the enclosure if it excludes zero; otherwise the enclosure is refined. Zero is certified by proving that the ball with the real (or imaginary) part set to zero contains a root of the minimal polynomial, which by uniqueness must be x. A real part can only be zero if the minimal polynomial is even, which is checked first. See Algebraic numbers by minimal polynomial and isolating ball.
Cite this page
The FLINT team, “qqbar_sgn_re, qqbar_sgn_im (qqbar.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/qqbar/qqbar_sgn_re.html (generated 2026-10-20).
@misc{flint-doc-qqbar-qqbar-sgn-re,
author = {{The FLINT team}},
title = {{qqbar\_sgn\_re, qqbar\_sgn\_im (qqbar.h)}},
howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
year = {2026},
url = {https://flintlib.org/doc/qqbar/qqbar_sgn_re.html},
note = {Generated 2026-10-20}
}